Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 7118 insertions, 0 deletions

diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
new file mode 100644
index 0000000..d2c0ed3
--- /dev/null
+++ b/src/bin/pgbench/pgbench.c
@@ -0,0 +1,7118 @@
+/*
+ * pgbench.c
+ *
+ * A simple benchmark program for PostgreSQL
+ * Originally written by Tatsuo Ishii and enhanced by many contributors.
+ *
+ * src/bin/pgbench/pgbench.c
+ * Copyright (c) 2000-2021, PostgreSQL Global Development Group
+ * ALL RIGHTS RESERVED;
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without a written agreement
+ * is hereby granted, provided that the above copyright notice and this
+ * paragraph and the following two paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ */
+
+#ifdef WIN32
+#define FD_SETSIZE 1024			/* must set before winsock2.h is included */
+#endif
+
+#include "postgres_fe.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <limits.h>
+#include <math.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>		/* for getrlimit */
+#endif
+
+/* For testing, PGBENCH_USE_SELECT can be defined to force use of that code */
+#if defined(HAVE_PPOLL) && !defined(PGBENCH_USE_SELECT)
+#define POLL_USING_PPOLL
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#endif
+#else							/* no ppoll(), so use select() */
+#define POLL_USING_SELECT
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#endif
+
+#include "common/int.h"
+#include "common/logging.h"
+#include "common/string.h"
+#include "common/username.h"
+#include "fe_utils/cancel.h"
+#include "fe_utils/conditional.h"
+#include "fe_utils/string_utils.h"
+#include "getopt_long.h"
+#include "libpq-fe.h"
+#include "pgbench.h"
+#include "port/pg_bitutils.h"
+#include "portability/instr_time.h"
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+#define ERRCODE_UNDEFINED_TABLE  "42P01"
+
+/*
+ * Hashing constants
+ */
+#define FNV_PRIME			UINT64CONST(0x100000001b3)
+#define FNV_OFFSET_BASIS	UINT64CONST(0xcbf29ce484222325)
+#define MM2_MUL				UINT64CONST(0xc6a4a7935bd1e995)
+#define MM2_MUL_TIMES_8		UINT64CONST(0x35253c9ade8f4ca8)
+#define MM2_ROT				47
+
+/*
+ * Multi-platform socket set implementations
+ */
+
+#ifdef POLL_USING_PPOLL
+#define SOCKET_WAIT_METHOD "ppoll"
+
+typedef struct socket_set
+{
+	int			maxfds;			/* allocated length of pollfds[] array */
+	int			curfds;			/* number currently in use */
+	struct pollfd pollfds[FLEXIBLE_ARRAY_MEMBER];
+} socket_set;
+
+#endif							/* POLL_USING_PPOLL */
+
+#ifdef POLL_USING_SELECT
+#define SOCKET_WAIT_METHOD "select"
+
+typedef struct socket_set
+{
+	int			maxfd;			/* largest FD currently set in fds */
+	fd_set		fds;
+} socket_set;
+
+#endif							/* POLL_USING_SELECT */
+
+/*
+ * Multi-platform thread implementations
+ */
+
+#ifdef WIN32
+/* Use Windows threads */
+#include <windows.h>
+#define GETERRNO() (_dosmaperr(GetLastError()), errno)
+#define THREAD_T HANDLE
+#define THREAD_FUNC_RETURN_TYPE unsigned
+#define THREAD_FUNC_RETURN return 0
+#define THREAD_FUNC_CC __stdcall
+#define THREAD_CREATE(handle, function, arg) \
+	((*(handle) = (HANDLE) _beginthreadex(NULL, 0, (function), (arg), 0, NULL)) == 0 ? errno : 0)
+#define THREAD_JOIN(handle) \
+	(WaitForSingleObject(handle, INFINITE) != WAIT_OBJECT_0 ? \
+	GETERRNO() : CloseHandle(handle) ? 0 : GETERRNO())
+#define THREAD_BARRIER_T SYNCHRONIZATION_BARRIER
+#define THREAD_BARRIER_INIT(barrier, n) \
+	(InitializeSynchronizationBarrier((barrier), (n), 0) ? 0 : GETERRNO())
+#define THREAD_BARRIER_WAIT(barrier) \
+	EnterSynchronizationBarrier((barrier), \
+								SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY)
+#define THREAD_BARRIER_DESTROY(barrier)
+#elif defined(ENABLE_THREAD_SAFETY)
+/* Use POSIX threads */
+#include "port/pg_pthread.h"
+#define THREAD_T pthread_t
+#define THREAD_FUNC_RETURN_TYPE void *
+#define THREAD_FUNC_RETURN return NULL
+#define THREAD_FUNC_CC
+#define THREAD_CREATE(handle, function, arg) \
+	pthread_create((handle), NULL, (function), (arg))
+#define THREAD_JOIN(handle) \
+	pthread_join((handle), NULL)
+#define THREAD_BARRIER_T pthread_barrier_t
+#define THREAD_BARRIER_INIT(barrier, n) \
+	pthread_barrier_init((barrier), NULL, (n))
+#define THREAD_BARRIER_WAIT(barrier) pthread_barrier_wait((barrier))
+#define THREAD_BARRIER_DESTROY(barrier) pthread_barrier_destroy((barrier))
+#else
+/* No threads implementation, use none (-j 1) */
+#define THREAD_T void *
+#define THREAD_FUNC_RETURN_TYPE void *
+#define THREAD_FUNC_RETURN return NULL
+#define THREAD_FUNC_CC
+#define THREAD_BARRIER_T int
+#define THREAD_BARRIER_INIT(barrier, n) (*(barrier) = 0)
+#define THREAD_BARRIER_WAIT(barrier)
+#define THREAD_BARRIER_DESTROY(barrier)
+#endif
+
+
+/********************************************************************
+ * some configurable parameters */
+
+#define DEFAULT_INIT_STEPS "dtgvp"	/* default -I setting */
+#define ALL_INIT_STEPS "dtgGvpf"	/* all possible steps */
+
+#define LOG_STEP_SECONDS	5	/* seconds between log messages */
+#define DEFAULT_NXACTS	10		/* default nxacts */
+
+#define MIN_GAUSSIAN_PARAM		2.0 /* minimum parameter for gauss */
+
+#define MIN_ZIPFIAN_PARAM		1.001	/* minimum parameter for zipfian */
+#define MAX_ZIPFIAN_PARAM		1000.0	/* maximum parameter for zipfian */
+
+int			nxacts = 0;			/* number of transactions per client */
+int			duration = 0;		/* duration in seconds */
+int64		end_time = 0;		/* when to stop in micro seconds, under -T */
+
+/*
+ * scaling factor. for example, scale = 10 will make 1000000 tuples in
+ * pgbench_accounts table.
+ */
+int			scale = 1;
+
+/*
+ * fillfactor. for example, fillfactor = 90 will use only 90 percent
+ * space during inserts and leave 10 percent free.
+ */
+int			fillfactor = 100;
+
+/*
+ * use unlogged tables?
+ */
+bool		unlogged_tables = false;
+
+/*
+ * log sampling rate (1.0 = log everything, 0.0 = option not given)
+ */
+double		sample_rate = 0.0;
+
+/*
+ * When threads are throttled to a given rate limit, this is the target delay
+ * to reach that rate in usec.  0 is the default and means no throttling.
+ */
+double		throttle_delay = 0;
+
+/*
+ * Transactions which take longer than this limit (in usec) are counted as
+ * late, and reported as such, although they are completed anyway. When
+ * throttling is enabled, execution time slots that are more than this late
+ * are skipped altogether, and counted separately.
+ */
+int64		latency_limit = 0;
+
+/*
+ * tablespace selection
+ */
+char	   *tablespace = NULL;
+char	   *index_tablespace = NULL;
+
+/*
+ * Number of "pgbench_accounts" partitions.  0 is the default and means no
+ * partitioning.
+ */
+static int	partitions = 0;
+
+/* partitioning strategy for "pgbench_accounts" */
+typedef enum
+{
+	PART_NONE,					/* no partitioning */
+	PART_RANGE,					/* range partitioning */
+	PART_HASH					/* hash partitioning */
+} partition_method_t;
+
+static partition_method_t partition_method = PART_NONE;
+static const char *PARTITION_METHOD[] = {"none", "range", "hash"};
+
+/* random seed used to initialize base_random_sequence */
+int64		random_seed = -1;
+
+/*
+ * end of configurable parameters
+ *********************************************************************/
+
+#define nbranches	1			/* Makes little sense to change this.  Change
+								 * -s instead */
+#define ntellers	10
+#define naccounts	100000
+
+/*
+ * The scale factor at/beyond which 32bit integers are incapable of storing
+ * 64bit values.
+ *
+ * Although the actual threshold is 21474, we use 20000 because it is easier to
+ * document and remember, and isn't that far away from the real threshold.
+ */
+#define SCALE_32BIT_THRESHOLD 20000
+
+bool		use_log;			/* log transaction latencies to a file */
+bool		use_quiet;			/* quiet logging onto stderr */
+int			agg_interval;		/* log aggregates instead of individual
+								 * transactions */
+bool		per_script_stats = false;	/* whether to collect stats per script */
+int			progress = 0;		/* thread progress report every this seconds */
+bool		progress_timestamp = false; /* progress report with Unix time */
+int			nclients = 1;		/* number of clients */
+int			nthreads = 1;		/* number of threads */
+bool		is_connect;			/* establish connection for each transaction */
+bool		report_per_command; /* report per-command latencies */
+int			main_pid;			/* main process id used in log filename */
+
+const char *pghost = NULL;
+const char *pgport = NULL;
+const char *username = NULL;
+const char *dbName = NULL;
+char	   *logfile_prefix = NULL;
+const char *progname;
+
+#define WSEP '@'				/* weight separator */
+
+volatile bool timer_exceeded = false;	/* flag from signal handler */
+
+/*
+ * Variable definitions.
+ *
+ * If a variable only has a string value, "svalue" is that value, and value is
+ * "not set".  If the value is known, "value" contains the value (in any
+ * variant).
+ *
+ * In this case "svalue" contains the string equivalent of the value, if we've
+ * had occasion to compute that, or NULL if we haven't.
+ */
+typedef struct
+{
+	char	   *name;			/* variable's name */
+	char	   *svalue;			/* its value in string form, if known */
+	PgBenchValue value;			/* actual variable's value */
+} Variable;
+
+#define MAX_SCRIPTS		128		/* max number of SQL scripts allowed */
+#define SHELL_COMMAND_SIZE	256 /* maximum size allowed for shell command */
+
+/*
+ * Simple data structure to keep stats about something.
+ *
+ * XXX probably the first value should be kept and used as an offset for
+ * better numerical stability...
+ */
+typedef struct SimpleStats
+{
+	int64		count;			/* how many values were encountered */
+	double		min;			/* the minimum seen */
+	double		max;			/* the maximum seen */
+	double		sum;			/* sum of values */
+	double		sum2;			/* sum of squared values */
+} SimpleStats;
+
+/*
+ * The instr_time type is expensive when dealing with time arithmetic.  Define
+ * a type to hold microseconds instead.  Type int64 is good enough for about
+ * 584500 years.
+ */
+typedef int64 pg_time_usec_t;
+
+/*
+ * Data structure to hold various statistics: per-thread and per-script stats
+ * are maintained and merged together.
+ */
+typedef struct StatsData
+{
+	pg_time_usec_t start_time;	/* interval start time, for aggregates */
+	int64		cnt;			/* number of transactions, including skipped */
+	int64		skipped;		/* number of transactions skipped under --rate
+								 * and --latency-limit */
+	SimpleStats latency;
+	SimpleStats lag;
+} StatsData;
+
+/*
+ * For displaying Unix epoch timestamps, as some time functions may have
+ * another reference.
+ */
+pg_time_usec_t epoch_shift;
+
+/*
+ * Struct to keep random state.
+ */
+typedef struct RandomState
+{
+	unsigned short xseed[3];
+} RandomState;
+
+/* Various random sequences are initialized from this one. */
+static RandomState base_random_sequence;
+
+/* Synchronization barrier for start and connection */
+static THREAD_BARRIER_T barrier;
+
+/*
+ * Connection state machine states.
+ */
+typedef enum
+{
+	/*
+	 * The client must first choose a script to execute.  Once chosen, it can
+	 * either be throttled (state CSTATE_PREPARE_THROTTLE under --rate), start
+	 * right away (state CSTATE_START_TX) or not start at all if the timer was
+	 * exceeded (state CSTATE_FINISHED).
+	 */
+	CSTATE_CHOOSE_SCRIPT,
+
+	/*
+	 * CSTATE_START_TX performs start-of-transaction processing.  Establishes
+	 * a new connection for the transaction in --connect mode, records the
+	 * transaction start time, and proceed to the first command.
+	 *
+	 * Note: once a script is started, it will either error or run till its
+	 * end, where it may be interrupted. It is not interrupted while running,
+	 * so pgbench --time is to be understood as tx are allowed to start in
+	 * that time, and will finish when their work is completed.
+	 */
+	CSTATE_START_TX,
+
+	/*
+	 * In CSTATE_PREPARE_THROTTLE state, we calculate when to begin the next
+	 * transaction, and advance to CSTATE_THROTTLE.  CSTATE_THROTTLE state
+	 * sleeps until that moment, then advances to CSTATE_START_TX, or
+	 * CSTATE_FINISHED if the next transaction would start beyond the end of
+	 * the run.
+	 */
+	CSTATE_PREPARE_THROTTLE,
+	CSTATE_THROTTLE,
+
+	/*
+	 * We loop through these states, to process each command in the script:
+	 *
+	 * CSTATE_START_COMMAND starts the execution of a command.  On a SQL
+	 * command, the command is sent to the server, and we move to
+	 * CSTATE_WAIT_RESULT state unless in pipeline mode. On a \sleep
+	 * meta-command, the timer is set, and we enter the CSTATE_SLEEP state to
+	 * wait for it to expire. Other meta-commands are executed immediately. If
+	 * the command about to start is actually beyond the end of the script,
+	 * advance to CSTATE_END_TX.
+	 *
+	 * CSTATE_WAIT_RESULT waits until we get a result set back from the server
+	 * for the current command.
+	 *
+	 * CSTATE_SLEEP waits until the end of \sleep.
+	 *
+	 * CSTATE_END_COMMAND records the end-of-command timestamp, increments the
+	 * command counter, and loops back to CSTATE_START_COMMAND state.
+	 *
+	 * CSTATE_SKIP_COMMAND is used by conditional branches which are not
+	 * executed. It quickly skip commands that do not need any evaluation.
+	 * This state can move forward several commands, till there is something
+	 * to do or the end of the script.
+	 */
+	CSTATE_START_COMMAND,
+	CSTATE_WAIT_RESULT,
+	CSTATE_SLEEP,
+	CSTATE_END_COMMAND,
+	CSTATE_SKIP_COMMAND,
+
+	/*
+	 * CSTATE_END_TX performs end-of-transaction processing.  It calculates
+	 * latency, and logs the transaction.  In --connect mode, it closes the
+	 * current connection.
+	 *
+	 * Then either starts over in CSTATE_CHOOSE_SCRIPT, or enters
+	 * CSTATE_FINISHED if we have no more work to do.
+	 */
+	CSTATE_END_TX,
+
+	/*
+	 * Final states.  CSTATE_ABORTED means that the script execution was
+	 * aborted because a command failed, CSTATE_FINISHED means success.
+	 */
+	CSTATE_ABORTED,
+	CSTATE_FINISHED
+} ConnectionStateEnum;
+
+/*
+ * Connection state.
+ */
+typedef struct
+{
+	PGconn	   *con;			/* connection handle to DB */
+	int			id;				/* client No. */
+	ConnectionStateEnum state;	/* state machine's current state. */
+	ConditionalStack cstack;	/* enclosing conditionals state */
+
+	/*
+	 * Separate randomness for each client. This is used for random functions
+	 * PGBENCH_RANDOM_* during the execution of the script.
+	 */
+	RandomState cs_func_rs;
+
+	int			use_file;		/* index in sql_script for this client */
+	int			command;		/* command number in script */
+
+	/* client variables */
+	Variable   *variables;		/* array of variable definitions */
+	int			nvariables;		/* number of variables */
+	bool		vars_sorted;	/* are variables sorted by name? */
+
+	/* various times about current transaction in microseconds */
+	pg_time_usec_t txn_scheduled;	/* scheduled start time of transaction */
+	pg_time_usec_t sleep_until; /* scheduled start time of next cmd */
+	pg_time_usec_t txn_begin;	/* used for measuring schedule lag times */
+	pg_time_usec_t stmt_begin;	/* used for measuring statement latencies */
+
+	bool		prepared[MAX_SCRIPTS];	/* whether client prepared the script */
+
+	/* per client collected stats */
+	int64		cnt;			/* client transaction count, for -t */
+} CState;
+
+/*
+ * Thread state
+ */
+typedef struct
+{
+	int			tid;			/* thread id */
+	THREAD_T	thread;			/* thread handle */
+	CState	   *state;			/* array of CState */
+	int			nstate;			/* length of state[] */
+
+	/*
+	 * Separate randomness for each thread. Each thread option uses its own
+	 * random state to make all of them independent of each other and
+	 * therefore deterministic at the thread level.
+	 */
+	RandomState ts_choose_rs;	/* random state for selecting a script */
+	RandomState ts_throttle_rs; /* random state for transaction throttling */
+	RandomState ts_sample_rs;	/* random state for log sampling */
+
+	int64		throttle_trigger;	/* previous/next throttling (us) */
+	FILE	   *logfile;		/* where to log, or NULL */
+
+	/* per thread collected stats in microseconds */
+	pg_time_usec_t create_time; /* thread creation time */
+	pg_time_usec_t started_time;	/* thread is running */
+	pg_time_usec_t bench_start; /* thread is benchmarking */
+	pg_time_usec_t conn_duration;	/* cumulated connection and deconnection
+									 * delays */
+
+	StatsData	stats;
+	int64		latency_late;	/* count executed but late transactions */
+} TState;
+
+/*
+ * queries read from files
+ */
+#define SQL_COMMAND		1
+#define META_COMMAND	2
+
+/*
+ * max number of backslash command arguments or SQL variables,
+ * including the command or SQL statement itself
+ */
+#define MAX_ARGS		256
+
+typedef enum MetaCommand
+{
+	META_NONE,					/* not a known meta-command */
+	META_SET,					/* \set */
+	META_SETSHELL,				/* \setshell */
+	META_SHELL,					/* \shell */
+	META_SLEEP,					/* \sleep */
+	META_GSET,					/* \gset */
+	META_ASET,					/* \aset */
+	META_IF,					/* \if */
+	META_ELIF,					/* \elif */
+	META_ELSE,					/* \else */
+	META_ENDIF,					/* \endif */
+	META_STARTPIPELINE,			/* \startpipeline */
+	META_ENDPIPELINE			/* \endpipeline */
+} MetaCommand;
+
+typedef enum QueryMode
+{
+	QUERY_SIMPLE,				/* simple query */
+	QUERY_EXTENDED,				/* extended query */
+	QUERY_PREPARED,				/* extended query with prepared statements */
+	NUM_QUERYMODE
+} QueryMode;
+
+static QueryMode querymode = QUERY_SIMPLE;
+static const char *QUERYMODE[] = {"simple", "extended", "prepared"};
+
+/*
+ * struct Command represents one command in a script.
+ *
+ * lines		The raw, possibly multi-line command text.  Variable substitution
+ *				not applied.
+ * first_line	A short, single-line extract of 'lines', for error reporting.
+ * type			SQL_COMMAND or META_COMMAND
+ * meta			The type of meta-command, with META_NONE/GSET/ASET if command
+ *				is SQL.
+ * argc			Number of arguments of the command, 0 if not yet processed.
+ * argv			Command arguments, the first of which is the command or SQL
+ *				string itself.  For SQL commands, after post-processing
+ *				argv[0] is the same as 'lines' with variables substituted.
+ * varprefix 	SQL commands terminated with \gset or \aset have this set
+ *				to a non NULL value.  If nonempty, it's used to prefix the
+ *				variable name that receives the value.
+ * aset			do gset on all possible queries of a combined query (\;).
+ * expr			Parsed expression, if needed.
+ * stats		Time spent in this command.
+ */
+typedef struct Command
+{
+	PQExpBufferData lines;
+	char	   *first_line;
+	int			type;
+	MetaCommand meta;
+	int			argc;
+	char	   *argv[MAX_ARGS];
+	char	   *varprefix;
+	PgBenchExpr *expr;
+	SimpleStats stats;
+} Command;
+
+typedef struct ParsedScript
+{
+	const char *desc;			/* script descriptor (eg, file name) */
+	int			weight;			/* selection weight */
+	Command   **commands;		/* NULL-terminated array of Commands */
+	StatsData	stats;			/* total time spent in script */
+} ParsedScript;
+
+static ParsedScript sql_script[MAX_SCRIPTS];	/* SQL script files */
+static int	num_scripts;		/* number of scripts in sql_script[] */
+static int64 total_weight = 0;
+
+/* Builtin test scripts */
+typedef struct BuiltinScript
+{
+	const char *name;			/* very short name for -b ... */
+	const char *desc;			/* short description */
+	const char *script;			/* actual pgbench script */
+} BuiltinScript;
+
+static const BuiltinScript builtin_script[] =
+{
+	{
+		"tpcb-like",
+		"<builtin: TPC-B (sort of)>",
+		"\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
+		"\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
+		"\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
+		"\\set delta random(-5000, 5000)\n"
+		"BEGIN;\n"
+		"UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
+		"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
+		"UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;\n"
+		"UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;\n"
+		"INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
+		"END;\n"
+	},
+	{
+		"simple-update",
+		"<builtin: simple update>",
+		"\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
+		"\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
+		"\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
+		"\\set delta random(-5000, 5000)\n"
+		"BEGIN;\n"
+		"UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
+		"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
+		"INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
+		"END;\n"
+	},
+	{
+		"select-only",
+		"<builtin: select only>",
+		"\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
+		"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
+	}
+};
+
+
+/* Function prototypes */
+static void setNullValue(PgBenchValue *pv);
+static void setBoolValue(PgBenchValue *pv, bool bval);
+static void setIntValue(PgBenchValue *pv, int64 ival);
+static void setDoubleValue(PgBenchValue *pv, double dval);
+static bool evaluateExpr(CState *st, PgBenchExpr *expr,
+						 PgBenchValue *retval);
+static ConnectionStateEnum executeMetaCommand(CState *st, pg_time_usec_t *now);
+static void doLog(TState *thread, CState *st,
+				  StatsData *agg, bool skipped, double latency, double lag);
+static void processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
+							 bool skipped, StatsData *agg);
+static void addScript(ParsedScript script);
+static THREAD_FUNC_RETURN_TYPE THREAD_FUNC_CC threadRun(void *arg);
+static void finishCon(CState *st);
+static void setalarm(int seconds);
+static socket_set *alloc_socket_set(int count);
+static void free_socket_set(socket_set *sa);
+static void clear_socket_set(socket_set *sa);
+static void add_socket_to_set(socket_set *sa, int fd, int idx);
+static int	wait_on_socket_set(socket_set *sa, int64 usecs);
+static bool socket_has_input(socket_set *sa, int fd, int idx);
+
+
+/* callback functions for our flex lexer */
+static const PsqlScanCallbacks pgbench_callbacks = {
+	NULL,						/* don't need get_variable functionality */
+};
+
+static inline pg_time_usec_t
+pg_time_now(void)
+{
+	instr_time	now;
+
+	INSTR_TIME_SET_CURRENT(now);
+
+	return (pg_time_usec_t) INSTR_TIME_GET_MICROSEC(now);
+}
+
+static inline void
+pg_time_now_lazy(pg_time_usec_t *now)
+{
+	if ((*now) == 0)
+		(*now) = pg_time_now();
+}
+
+#define PG_TIME_GET_DOUBLE(t) (0.000001 * (t))
+
+static void
+usage(void)
+{
+	printf("%s is a benchmarking tool for PostgreSQL.\n\n"
+		   "Usage:\n"
+		   "  %s [OPTION]... [DBNAME]\n"
+		   "\nInitialization options:\n"
+		   "  -i, --initialize         invokes initialization mode\n"
+		   "  -I, --init-steps=[" ALL_INIT_STEPS "]+ (default \"" DEFAULT_INIT_STEPS "\")\n"
+		   "                           run selected initialization steps\n"
+		   "  -F, --fillfactor=NUM     set fill factor\n"
+		   "  -n, --no-vacuum          do not run VACUUM during initialization\n"
+		   "  -q, --quiet              quiet logging (one message each 5 seconds)\n"
+		   "  -s, --scale=NUM          scaling factor\n"
+		   "  --foreign-keys           create foreign key constraints between tables\n"
+		   "  --index-tablespace=TABLESPACE\n"
+		   "                           create indexes in the specified tablespace\n"
+		   "  --partition-method=(range|hash)\n"
+		   "                           partition pgbench_accounts with this method (default: range)\n"
+		   "  --partitions=NUM         partition pgbench_accounts into NUM parts (default: 0)\n"
+		   "  --tablespace=TABLESPACE  create tables in the specified tablespace\n"
+		   "  --unlogged-tables        create tables as unlogged tables\n"
+		   "\nOptions to select what to run:\n"
+		   "  -b, --builtin=NAME[@W]   add builtin script NAME weighted at W (default: 1)\n"
+		   "                           (use \"-b list\" to list available scripts)\n"
+		   "  -f, --file=FILENAME[@W]  add script FILENAME weighted at W (default: 1)\n"
+		   "  -N, --skip-some-updates  skip updates of pgbench_tellers and pgbench_branches\n"
+		   "                           (same as \"-b simple-update\")\n"
+		   "  -S, --select-only        perform SELECT-only transactions\n"
+		   "                           (same as \"-b select-only\")\n"
+		   "\nBenchmarking options:\n"
+		   "  -c, --client=NUM         number of concurrent database clients (default: 1)\n"
+		   "  -C, --connect            establish new connection for each transaction\n"
+		   "  -D, --define=VARNAME=VALUE\n"
+		   "                           define variable for use by custom script\n"
+		   "  -j, --jobs=NUM           number of threads (default: 1)\n"
+		   "  -l, --log                write transaction times to log file\n"
+		   "  -L, --latency-limit=NUM  count transactions lasting more than NUM ms as late\n"
+		   "  -M, --protocol=simple|extended|prepared\n"
+		   "                           protocol for submitting queries (default: simple)\n"
+		   "  -n, --no-vacuum          do not run VACUUM before tests\n"
+		   "  -P, --progress=NUM       show thread progress report every NUM seconds\n"
+		   "  -r, --report-latencies   report average latency per command\n"
+		   "  -R, --rate=NUM           target rate in transactions per second\n"
+		   "  -s, --scale=NUM          report this scale factor in output\n"
+		   "  -t, --transactions=NUM   number of transactions each client runs (default: 10)\n"
+		   "  -T, --time=NUM           duration of benchmark test in seconds\n"
+		   "  -v, --vacuum-all         vacuum all four standard tables before tests\n"
+		   "  --aggregate-interval=NUM aggregate data over NUM seconds\n"
+		   "  --log-prefix=PREFIX      prefix for transaction time log file\n"
+		   "                           (default: \"pgbench_log\")\n"
+		   "  --progress-timestamp     use Unix epoch timestamps for progress\n"
+		   "  --random-seed=SEED       set random seed (\"time\", \"rand\", integer)\n"
+		   "  --sampling-rate=NUM      fraction of transactions to log (e.g., 0.01 for 1%%)\n"
+		   "  --show-script=NAME       show builtin script code, then exit\n"
+		   "\nCommon options:\n"
+		   "  -d, --debug              print debugging output\n"
+		   "  -h, --host=HOSTNAME      database server host or socket directory\n"
+		   "  -p, --port=PORT          database server port number\n"
+		   "  -U, --username=USERNAME  connect as specified database user\n"
+		   "  -V, --version            output version information, then exit\n"
+		   "  -?, --help               show this help, then exit\n"
+		   "\n"
+		   "Report bugs to <%s>.\n"
+		   "%s home page: <%s>\n",
+		   progname, progname, PACKAGE_BUGREPORT, PACKAGE_NAME, PACKAGE_URL);
+}
+
+/* return whether str matches "^\s*[-+]?[0-9]+$" */
+static bool
+is_an_int(const char *str)
+{
+	const char *ptr = str;
+
+	/* skip leading spaces; cast is consistent with strtoint64 */
+	while (*ptr && isspace((unsigned char) *ptr))
+		ptr++;
+
+	/* skip sign */
+	if (*ptr == '+' || *ptr == '-')
+		ptr++;
+
+	/* at least one digit */
+	if (*ptr && !isdigit((unsigned char) *ptr))
+		return false;
+
+	/* eat all digits */
+	while (*ptr && isdigit((unsigned char) *ptr))
+		ptr++;
+
+	/* must have reached end of string */
+	return *ptr == '\0';
+}
+
+
+/*
+ * strtoint64 -- convert a string to 64-bit integer
+ *
+ * This function is a slightly modified version of scanint8() from
+ * src/backend/utils/adt/int8.c.
+ *
+ * The function returns whether the conversion worked, and if so
+ * "*result" is set to the result.
+ *
+ * If not errorOK, an error message is also printed out on errors.
+ */
+bool
+strtoint64(const char *str, bool errorOK, int64 *result)
+{
+	const char *ptr = str;
+	int64		tmp = 0;
+	bool		neg = false;
+
+	/*
+	 * Do our own scan, rather than relying on sscanf which might be broken
+	 * for long long.
+	 *
+	 * As INT64_MIN can't be stored as a positive 64 bit integer, accumulate
+	 * value as a negative number.
+	 */
+
+	/* skip leading spaces */
+	while (*ptr && isspace((unsigned char) *ptr))
+		ptr++;
+
+	/* handle sign */
+	if (*ptr == '-')
+	{
+		ptr++;
+		neg = true;
+	}
+	else if (*ptr == '+')
+		ptr++;
+
+	/* require at least one digit */
+	if (unlikely(!isdigit((unsigned char) *ptr)))
+		goto invalid_syntax;
+
+	/* process digits */
+	while (*ptr && isdigit((unsigned char) *ptr))
+	{
+		int8		digit = (*ptr++ - '0');
+
+		if (unlikely(pg_mul_s64_overflow(tmp, 10, &tmp)) ||
+			unlikely(pg_sub_s64_overflow(tmp, digit, &tmp)))
+			goto out_of_range;
+	}
+
+	/* allow trailing whitespace, but not other trailing chars */
+	while (*ptr != '\0' && isspace((unsigned char) *ptr))
+		ptr++;
+
+	if (unlikely(*ptr != '\0'))
+		goto invalid_syntax;
+
+	if (!neg)
+	{
+		if (unlikely(tmp == PG_INT64_MIN))
+			goto out_of_range;
+		tmp = -tmp;
+	}
+
+	*result = tmp;
+	return true;
+
+out_of_range:
+	if (!errorOK)
+		pg_log_error("value \"%s\" is out of range for type bigint", str);
+	return false;
+
+invalid_syntax:
+	if (!errorOK)
+		pg_log_error("invalid input syntax for type bigint: \"%s\"", str);
+	return false;
+}
+
+/* convert string to double, detecting overflows/underflows */
+bool
+strtodouble(const char *str, bool errorOK, double *dv)
+{
+	char	   *end;
+
+	errno = 0;
+	*dv = strtod(str, &end);
+
+	if (unlikely(errno != 0))
+	{
+		if (!errorOK)
+			pg_log_error("value \"%s\" is out of range for type double", str);
+		return false;
+	}
+
+	if (unlikely(end == str || *end != '\0'))
+	{
+		if (!errorOK)
+			pg_log_error("invalid input syntax for type double: \"%s\"", str);
+		return false;
+	}
+	return true;
+}
+
+/*
+ * Initialize a random state struct.
+ *
+ * We derive the seed from base_random_sequence, which must be set up already.
+ */
+static void
+initRandomState(RandomState *random_state)
+{
+	random_state->xseed[0] = (unsigned short)
+		(pg_jrand48(base_random_sequence.xseed) & 0xFFFF);
+	random_state->xseed[1] = (unsigned short)
+		(pg_jrand48(base_random_sequence.xseed) & 0xFFFF);
+	random_state->xseed[2] = (unsigned short)
+		(pg_jrand48(base_random_sequence.xseed) & 0xFFFF);
+}
+
+/*
+ * Random number generator: uniform distribution from min to max inclusive.
+ *
+ * Although the limits are expressed as int64, you can't generate the full
+ * int64 range in one call, because the difference of the limits mustn't
+ * overflow int64.  In practice it's unwise to ask for more than an int32
+ * range, because of the limited precision of pg_erand48().
+ */
+static int64
+getrand(RandomState *random_state, int64 min, int64 max)
+{
+	/*
+	 * Odd coding is so that min and max have approximately the same chance of
+	 * being selected as do numbers between them.
+	 *
+	 * pg_erand48() is thread-safe and concurrent, which is why we use it
+	 * rather than random(), which in glibc is non-reentrant, and therefore
+	 * protected by a mutex, and therefore a bottleneck on machines with many
+	 * CPUs.
+	 */
+	return min + (int64) ((max - min + 1) * pg_erand48(random_state->xseed));
+}
+
+/*
+ * random number generator: exponential distribution from min to max inclusive.
+ * the parameter is so that the density of probability for the last cut-off max
+ * value is exp(-parameter).
+ */
+static int64
+getExponentialRand(RandomState *random_state, int64 min, int64 max,
+				   double parameter)
+{
+	double		cut,
+				uniform,
+				rand;
+
+	/* abort if wrong parameter, but must really be checked beforehand */
+	Assert(parameter > 0.0);
+	cut = exp(-parameter);
+	/* erand in [0, 1), uniform in (0, 1] */
+	uniform = 1.0 - pg_erand48(random_state->xseed);
+
+	/*
+	 * inner expression in (cut, 1] (if parameter > 0), rand in [0, 1)
+	 */
+	Assert((1.0 - cut) != 0.0);
+	rand = -log(cut + (1.0 - cut) * uniform) / parameter;
+	/* return int64 random number within between min and max */
+	return min + (int64) ((max - min + 1) * rand);
+}
+
+/* random number generator: gaussian distribution from min to max inclusive */
+static int64
+getGaussianRand(RandomState *random_state, int64 min, int64 max,
+				double parameter)
+{
+	double		stdev;
+	double		rand;
+
+	/* abort if parameter is too low, but must really be checked beforehand */
+	Assert(parameter >= MIN_GAUSSIAN_PARAM);
+
+	/*
+	 * Get user specified random number from this loop, with -parameter <
+	 * stdev <= parameter
+	 *
+	 * This loop is executed until the number is in the expected range.
+	 *
+	 * As the minimum parameter is 2.0, the probability of looping is low:
+	 * sqrt(-2 ln(r)) <= 2 => r >= e^{-2} ~ 0.135, then when taking the
+	 * average sinus multiplier as 2/pi, we have a 8.6% looping probability in
+	 * the worst case. For a parameter value of 5.0, the looping probability
+	 * is about e^{-5} * 2 / pi ~ 0.43%.
+	 */
+	do
+	{
+		/*
+		 * pg_erand48 generates [0,1), but for the basic version of the
+		 * Box-Muller transform the two uniformly distributed random numbers
+		 * are expected in (0, 1] (see
+		 * https://en.wikipedia.org/wiki/Box-Muller_transform)
+		 */
+		double		rand1 = 1.0 - pg_erand48(random_state->xseed);
+		double		rand2 = 1.0 - pg_erand48(random_state->xseed);
+
+		/* Box-Muller basic form transform */
+		double		var_sqrt = sqrt(-2.0 * log(rand1));
+
+		stdev = var_sqrt * sin(2.0 * M_PI * rand2);
+
+		/*
+		 * we may try with cos, but there may be a bias induced if the
+		 * previous value fails the test. To be on the safe side, let us try
+		 * over.
+		 */
+	}
+	while (stdev < -parameter || stdev >= parameter);
+
+	/* stdev is in [-parameter, parameter), normalization to [0,1) */
+	rand = (stdev + parameter) / (parameter * 2.0);
+
+	/* return int64 random number within between min and max */
+	return min + (int64) ((max - min + 1) * rand);
+}
+
+/*
+ * random number generator: generate a value, such that the series of values
+ * will approximate a Poisson distribution centered on the given value.
+ *
+ * Individual results are rounded to integers, though the center value need
+ * not be one.
+ */
+static int64
+getPoissonRand(RandomState *random_state, double center)
+{
+	/*
+	 * Use inverse transform sampling to generate a value > 0, such that the
+	 * expected (i.e. average) value is the given argument.
+	 */
+	double		uniform;
+
+	/* erand in [0, 1), uniform in (0, 1] */
+	uniform = 1.0 - pg_erand48(random_state->xseed);
+
+	return (int64) (-log(uniform) * center + 0.5);
+}
+
+/*
+ * Computing zipfian using rejection method, based on
+ * "Non-Uniform Random Variate Generation",
+ * Luc Devroye, p. 550-551, Springer 1986.
+ *
+ * This works for s > 1.0, but may perform badly for s very close to 1.0.
+ */
+static int64
+computeIterativeZipfian(RandomState *random_state, int64 n, double s)
+{
+	double		b = pow(2.0, s - 1.0);
+	double		x,
+				t,
+				u,
+				v;
+
+	/* Ensure n is sane */
+	if (n <= 1)
+		return 1;
+
+	while (true)
+	{
+		/* random variates */
+		u = pg_erand48(random_state->xseed);
+		v = pg_erand48(random_state->xseed);
+
+		x = floor(pow(u, -1.0 / (s - 1.0)));
+
+		t = pow(1.0 + 1.0 / x, s - 1.0);
+		/* reject if too large or out of bound */
+		if (v * x * (t - 1.0) / (b - 1.0) <= t / b && x <= n)
+			break;
+	}
+	return (int64) x;
+}
+
+/* random number generator: zipfian distribution from min to max inclusive */
+static int64
+getZipfianRand(RandomState *random_state, int64 min, int64 max, double s)
+{
+	int64		n = max - min + 1;
+
+	/* abort if parameter is invalid */
+	Assert(MIN_ZIPFIAN_PARAM <= s && s <= MAX_ZIPFIAN_PARAM);
+
+	return min - 1 + computeIterativeZipfian(random_state, n, s);
+}
+
+/*
+ * FNV-1a hash function
+ */
+static int64
+getHashFnv1a(int64 val, uint64 seed)
+{
+	int64		result;
+	int			i;
+
+	result = FNV_OFFSET_BASIS ^ seed;
+	for (i = 0; i < 8; ++i)
+	{
+		int32		octet = val & 0xff;
+
+		val = val >> 8;
+		result = result ^ octet;
+		result = result * FNV_PRIME;
+	}
+
+	return result;
+}
+
+/*
+ * Murmur2 hash function
+ *
+ * Based on original work of Austin Appleby
+ * https://github.com/aappleby/smhasher/blob/master/src/MurmurHash2.cpp
+ */
+static int64
+getHashMurmur2(int64 val, uint64 seed)
+{
+	uint64		result = seed ^ MM2_MUL_TIMES_8;	/* sizeof(int64) */
+	uint64		k = (uint64) val;
+
+	k *= MM2_MUL;
+	k ^= k >> MM2_ROT;
+	k *= MM2_MUL;
+
+	result ^= k;
+	result *= MM2_MUL;
+
+	result ^= result >> MM2_ROT;
+	result *= MM2_MUL;
+	result ^= result >> MM2_ROT;
+
+	return (int64) result;
+}
+
+/*
+ * Pseudorandom permutation function
+ *
+ * For small sizes, this generates each of the (size!) possible permutations
+ * of integers in the range [0, size) with roughly equal probability.  Once
+ * the size is larger than 20, the number of possible permutations exceeds the
+ * number of distinct states of the internal pseudorandom number generators,
+ * and so not all possible permutations can be generated, but the permutations
+ * chosen should continue to give the appearance of being random.
+ *
+ * THIS FUNCTION IS NOT CRYPTOGRAPHICALLY SECURE.
+ * DO NOT USE FOR SUCH PURPOSE.
+ */
+static int64
+permute(const int64 val, const int64 isize, const int64 seed)
+{
+	RandomState random_state1;
+	RandomState random_state2;
+	uint64		size;
+	uint64		v;
+	int			masklen;
+	uint64		mask;
+	int			i;
+
+	if (isize < 2)
+		return 0;				/* nothing to permute */
+
+	/* Initialize a pair of random states using the seed */
+	random_state1.xseed[0] = seed & 0xFFFF;
+	random_state1.xseed[1] = (seed >> 16) & 0xFFFF;
+	random_state1.xseed[2] = (seed >> 32) & 0xFFFF;
+
+	random_state2.xseed[0] = (((uint64) seed) >> 48) & 0xFFFF;
+	random_state2.xseed[1] = seed & 0xFFFF;
+	random_state2.xseed[2] = (seed >> 16) & 0xFFFF;
+
+	/* Computations are performed on unsigned values */
+	size = (uint64) isize;
+	v = (uint64) val % size;
+
+	/* Mask to work modulo largest power of 2 less than or equal to size */
+	masklen = pg_leftmost_one_pos64(size);
+	mask = (((uint64) 1) << masklen) - 1;
+
+	/*
+	 * Permute the input value by applying several rounds of pseudorandom
+	 * bijective transformations.  The intention here is to distribute each
+	 * input uniformly randomly across the range, and separate adjacent inputs
+	 * approximately uniformly randomly from each other, leading to a fairly
+	 * random overall choice of permutation.
+	 *
+	 * To separate adjacent inputs, we multiply by a random number modulo
+	 * (mask + 1), which is a power of 2.  For this to be a bijection, the
+	 * multiplier must be odd.  Since this is known to lead to less randomness
+	 * in the lower bits, we also apply a rotation that shifts the topmost bit
+	 * into the least significant bit.  In the special cases where size <= 3,
+	 * mask = 1 and each of these operations is actually a no-op, so we also
+	 * XOR the value with a different random number to inject additional
+	 * randomness.  Since the size is generally not a power of 2, we apply
+	 * this bijection on overlapping upper and lower halves of the input.
+	 *
+	 * To distribute the inputs uniformly across the range, we then also apply
+	 * a random offset modulo the full range.
+	 *
+	 * Taken together, these operations resemble a modified linear
+	 * congruential generator, as is commonly used in pseudorandom number
+	 * generators.  The number of rounds is fairly arbitrary, but six has been
+	 * found empirically to give a fairly good tradeoff between performance
+	 * and uniform randomness.  For small sizes it selects each of the (size!)
+	 * possible permutations with roughly equal probability.  For larger
+	 * sizes, not all permutations can be generated, but the intended random
+	 * spread is still produced.
+	 */
+	for (i = 0; i < 6; i++)
+	{
+		uint64		m,
+					r,
+					t;
+
+		/* Random multiply (by an odd number), XOR and rotate of lower half */
+		m = (uint64) getrand(&random_state1, 0, mask) | 1;
+		r = (uint64) getrand(&random_state2, 0, mask);
+		if (v <= mask)
+		{
+			v = ((v * m) ^ r) & mask;
+			v = ((v << 1) & mask) | (v >> (masklen - 1));
+		}
+
+		/* Random multiply (by an odd number), XOR and rotate of upper half */
+		m = (uint64) getrand(&random_state1, 0, mask) | 1;
+		r = (uint64) getrand(&random_state2, 0, mask);
+		t = size - 1 - v;
+		if (t <= mask)
+		{
+			t = ((t * m) ^ r) & mask;
+			t = ((t << 1) & mask) | (t >> (masklen - 1));
+			v = size - 1 - t;
+		}
+
+		/* Random offset */
+		r = (uint64) getrand(&random_state2, 0, size - 1);
+		v = (v + r) % size;
+	}
+
+	return (int64) v;
+}
+
+/*
+ * Initialize the given SimpleStats struct to all zeroes
+ */
+static void
+initSimpleStats(SimpleStats *ss)
+{
+	memset(ss, 0, sizeof(SimpleStats));
+}
+
+/*
+ * Accumulate one value into a SimpleStats struct.
+ */
+static void
+addToSimpleStats(SimpleStats *ss, double val)
+{
+	if (ss->count == 0 || val < ss->min)
+		ss->min = val;
+	if (ss->count == 0 || val > ss->max)
+		ss->max = val;
+	ss->count++;
+	ss->sum += val;
+	ss->sum2 += val * val;
+}
+
+/*
+ * Merge two SimpleStats objects
+ */
+static void
+mergeSimpleStats(SimpleStats *acc, SimpleStats *ss)
+{
+	if (acc->count == 0 || ss->min < acc->min)
+		acc->min = ss->min;
+	if (acc->count == 0 || ss->max > acc->max)
+		acc->max = ss->max;
+	acc->count += ss->count;
+	acc->sum += ss->sum;
+	acc->sum2 += ss->sum2;
+}
+
+/*
+ * Initialize a StatsData struct to mostly zeroes, with its start time set to
+ * the given value.
+ */
+static void
+initStats(StatsData *sd, pg_time_usec_t start)
+{
+	sd->start_time = start;
+	sd->cnt = 0;
+	sd->skipped = 0;
+	initSimpleStats(&sd->latency);
+	initSimpleStats(&sd->lag);
+}
+
+/*
+ * Accumulate one additional item into the given stats object.
+ */
+static void
+accumStats(StatsData *stats, bool skipped, double lat, double lag)
+{
+	stats->cnt++;
+
+	if (skipped)
+	{
+		/* no latency to record on skipped transactions */
+		stats->skipped++;
+	}
+	else
+	{
+		addToSimpleStats(&stats->latency, lat);
+
+		/* and possibly the same for schedule lag */
+		if (throttle_delay)
+			addToSimpleStats(&stats->lag, lag);
+	}
+}
+
+/* call PQexec() and exit() on failure */
+static void
+executeStatement(PGconn *con, const char *sql)
+{
+	PGresult   *res;
+
+	res = PQexec(con, sql);
+	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	{
+		pg_log_fatal("query failed: %s", PQerrorMessage(con));
+		pg_log_info("query was: %s", sql);
+		exit(1);
+	}
+	PQclear(res);
+}
+
+/* call PQexec() and complain, but without exiting, on failure */
+static void
+tryExecuteStatement(PGconn *con, const char *sql)
+{
+	PGresult   *res;
+
+	res = PQexec(con, sql);
+	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	{
+		pg_log_error("%s", PQerrorMessage(con));
+		pg_log_info("(ignoring this error and continuing anyway)");
+	}
+	PQclear(res);
+}
+
+/* set up a connection to the backend */
+static PGconn *
+doConnect(void)
+{
+	PGconn	   *conn;
+	bool		new_pass;
+	static char *password = NULL;
+
+	/*
+	 * Start the connection.  Loop until we have a password if requested by
+	 * backend.
+	 */
+	do
+	{
+#define PARAMS_ARRAY_SIZE	7
+
+		const char *keywords[PARAMS_ARRAY_SIZE];
+		const char *values[PARAMS_ARRAY_SIZE];
+
+		keywords[0] = "host";
+		values[0] = pghost;
+		keywords[1] = "port";
+		values[1] = pgport;
+		keywords[2] = "user";
+		values[2] = username;
+		keywords[3] = "password";
+		values[3] = password;
+		keywords[4] = "dbname";
+		values[4] = dbName;
+		keywords[5] = "fallback_application_name";
+		values[5] = progname;
+		keywords[6] = NULL;
+		values[6] = NULL;
+
+		new_pass = false;
+
+		conn = PQconnectdbParams(keywords, values, true);
+
+		if (!conn)
+		{
+			pg_log_error("connection to database \"%s\" failed", dbName);
+			return NULL;
+		}
+
+		if (PQstatus(conn) == CONNECTION_BAD &&
+			PQconnectionNeedsPassword(conn) &&
+			!password)
+		{
+			PQfinish(conn);
+			password = simple_prompt("Password: ", false);
+			new_pass = true;
+		}
+	} while (new_pass);
+
+	/* check to see that the backend connection was successfully made */
+	if (PQstatus(conn) == CONNECTION_BAD)
+	{
+		pg_log_error("%s", PQerrorMessage(conn));
+		PQfinish(conn);
+		return NULL;
+	}
+
+	return conn;
+}
+
+/* qsort comparator for Variable array */
+static int
+compareVariableNames(const void *v1, const void *v2)
+{
+	return strcmp(((const Variable *) v1)->name,
+				  ((const Variable *) v2)->name);
+}
+
+/* Locate a variable by name; returns NULL if unknown */
+static Variable *
+lookupVariable(CState *st, char *name)
+{
+	Variable	key;
+
+	/* On some versions of Solaris, bsearch of zero items dumps core */
+	if (st->nvariables <= 0)
+		return NULL;
+
+	/* Sort if we have to */
+	if (!st->vars_sorted)
+	{
+		qsort((void *) st->variables, st->nvariables, sizeof(Variable),
+			  compareVariableNames);
+		st->vars_sorted = true;
+	}
+
+	/* Now we can search */
+	key.name = name;
+	return (Variable *) bsearch((void *) &key,
+								(void *) st->variables,
+								st->nvariables,
+								sizeof(Variable),
+								compareVariableNames);
+}
+
+/* Get the value of a variable, in string form; returns NULL if unknown */
+static char *
+getVariable(CState *st, char *name)
+{
+	Variable   *var;
+	char		stringform[64];
+
+	var = lookupVariable(st, name);
+	if (var == NULL)
+		return NULL;			/* not found */
+
+	if (var->svalue)
+		return var->svalue;		/* we have it in string form */
+
+	/* We need to produce a string equivalent of the value */
+	Assert(var->value.type != PGBT_NO_VALUE);
+	if (var->value.type == PGBT_NULL)
+		snprintf(stringform, sizeof(stringform), "NULL");
+	else if (var->value.type == PGBT_BOOLEAN)
+		snprintf(stringform, sizeof(stringform),
+				 "%s", var->value.u.bval ? "true" : "false");
+	else if (var->value.type == PGBT_INT)
+		snprintf(stringform, sizeof(stringform),
+				 INT64_FORMAT, var->value.u.ival);
+	else if (var->value.type == PGBT_DOUBLE)
+		snprintf(stringform, sizeof(stringform),
+				 "%.*g", DBL_DIG, var->value.u.dval);
+	else						/* internal error, unexpected type */
+		Assert(0);
+	var->svalue = pg_strdup(stringform);
+	return var->svalue;
+}
+
+/* Try to convert variable to a value; return false on failure */
+static bool
+makeVariableValue(Variable *var)
+{
+	size_t		slen;
+
+	if (var->value.type != PGBT_NO_VALUE)
+		return true;			/* no work */
+
+	slen = strlen(var->svalue);
+
+	if (slen == 0)
+		/* what should it do on ""? */
+		return false;
+
+	if (pg_strcasecmp(var->svalue, "null") == 0)
+	{
+		setNullValue(&var->value);
+	}
+
+	/*
+	 * accept prefixes such as y, ye, n, no... but not for "o". 0/1 are
+	 * recognized later as an int, which is converted to bool if needed.
+	 */
+	else if (pg_strncasecmp(var->svalue, "true", slen) == 0 ||
+			 pg_strncasecmp(var->svalue, "yes", slen) == 0 ||
+			 pg_strcasecmp(var->svalue, "on") == 0)
+	{
+		setBoolValue(&var->value, true);
+	}
+	else if (pg_strncasecmp(var->svalue, "false", slen) == 0 ||
+			 pg_strncasecmp(var->svalue, "no", slen) == 0 ||
+			 pg_strcasecmp(var->svalue, "off") == 0 ||
+			 pg_strcasecmp(var->svalue, "of") == 0)
+	{
+		setBoolValue(&var->value, false);
+	}
+	else if (is_an_int(var->svalue))
+	{
+		/* if it looks like an int, it must be an int without overflow */
+		int64		iv;
+
+		if (!strtoint64(var->svalue, false, &iv))
+			return false;
+
+		setIntValue(&var->value, iv);
+	}
+	else						/* type should be double */
+	{
+		double		dv;
+
+		if (!strtodouble(var->svalue, true, &dv))
+		{
+			pg_log_error("malformed variable \"%s\" value: \"%s\"",
+						 var->name, var->svalue);
+			return false;
+		}
+		setDoubleValue(&var->value, dv);
+	}
+	return true;
+}
+
+/*
+ * Check whether a variable's name is allowed.
+ *
+ * We allow any non-ASCII character, as well as ASCII letters, digits, and
+ * underscore.
+ *
+ * Keep this in sync with the definitions of variable name characters in
+ * "src/fe_utils/psqlscan.l", "src/bin/psql/psqlscanslash.l" and
+ * "src/bin/pgbench/exprscan.l".  Also see parseVariable(), below.
+ *
+ * Note: this static function is copied from "src/bin/psql/variables.c"
+ * but changed to disallow variable names starting with a digit.
+ */
+static bool
+valid_variable_name(const char *name)
+{
+	const unsigned char *ptr = (const unsigned char *) name;
+
+	/* Mustn't be zero-length */
+	if (*ptr == '\0')
+		return false;
+
+	/* must not start with [0-9] */
+	if (IS_HIGHBIT_SET(*ptr) ||
+		strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
+			   "_", *ptr) != NULL)
+		ptr++;
+	else
+		return false;
+
+	/* remaining characters can include [0-9] */
+	while (*ptr)
+	{
+		if (IS_HIGHBIT_SET(*ptr) ||
+			strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
+				   "_0123456789", *ptr) != NULL)
+			ptr++;
+		else
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * Lookup a variable by name, creating it if need be.
+ * Caller is expected to assign a value to the variable.
+ * Returns NULL on failure (bad name).
+ */
+static Variable *
+lookupCreateVariable(CState *st, const char *context, char *name)
+{
+	Variable   *var;
+
+	var = lookupVariable(st, name);
+	if (var == NULL)
+	{
+		Variable   *newvars;
+
+		/*
+		 * Check for the name only when declaring a new variable to avoid
+		 * overhead.
+		 */
+		if (!valid_variable_name(name))
+		{
+			pg_log_error("%s: invalid variable name: \"%s\"", context, name);
+			return NULL;
+		}
+
+		/* Create variable at the end of the array */
+		if (st->variables)
+			newvars = (Variable *) pg_realloc(st->variables,
+											  (st->nvariables + 1) * sizeof(Variable));
+		else
+			newvars = (Variable *) pg_malloc(sizeof(Variable));
+
+		st->variables = newvars;
+
+		var = &newvars[st->nvariables];
+
+		var->name = pg_strdup(name);
+		var->svalue = NULL;
+		/* caller is expected to initialize remaining fields */
+
+		st->nvariables++;
+		/* we don't re-sort the array till we have to */
+		st->vars_sorted = false;
+	}
+
+	return var;
+}
+
+/* Assign a string value to a variable, creating it if need be */
+/* Returns false on failure (bad name) */
+static bool
+putVariable(CState *st, const char *context, char *name, const char *value)
+{
+	Variable   *var;
+	char	   *val;
+
+	var = lookupCreateVariable(st, context, name);
+	if (!var)
+		return false;
+
+	/* dup then free, in case value is pointing at this variable */
+	val = pg_strdup(value);
+
+	if (var->svalue)
+		free(var->svalue);
+	var->svalue = val;
+	var->value.type = PGBT_NO_VALUE;
+
+	return true;
+}
+
+/* Assign a value to a variable, creating it if need be */
+/* Returns false on failure (bad name) */
+static bool
+putVariableValue(CState *st, const char *context, char *name,
+				 const PgBenchValue *value)
+{
+	Variable   *var;
+
+	var = lookupCreateVariable(st, context, name);
+	if (!var)
+		return false;
+
+	if (var->svalue)
+		free(var->svalue);
+	var->svalue = NULL;
+	var->value = *value;
+
+	return true;
+}
+
+/* Assign an integer value to a variable, creating it if need be */
+/* Returns false on failure (bad name) */
+static bool
+putVariableInt(CState *st, const char *context, char *name, int64 value)
+{
+	PgBenchValue val;
+
+	setIntValue(&val, value);
+	return putVariableValue(st, context, name, &val);
+}
+
+/*
+ * Parse a possible variable reference (:varname).
+ *
+ * "sql" points at a colon.  If what follows it looks like a valid
+ * variable name, return a malloc'd string containing the variable name,
+ * and set *eaten to the number of characters consumed (including the colon).
+ * Otherwise, return NULL.
+ */
+static char *
+parseVariable(const char *sql, int *eaten)
+{
+	int			i = 1;			/* starting at 1 skips the colon */
+	char	   *name;
+
+	/* keep this logic in sync with valid_variable_name() */
+	if (IS_HIGHBIT_SET(sql[i]) ||
+		strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
+			   "_", sql[i]) != NULL)
+		i++;
+	else
+		return NULL;
+
+	while (IS_HIGHBIT_SET(sql[i]) ||
+		   strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
+				  "_0123456789", sql[i]) != NULL)
+		i++;
+
+	name = pg_malloc(i);
+	memcpy(name, &sql[1], i - 1);
+	name[i - 1] = '\0';
+
+	*eaten = i;
+	return name;
+}
+
+static char *
+replaceVariable(char **sql, char *param, int len, char *value)
+{
+	int			valueln = strlen(value);
+
+	if (valueln > len)
+	{
+		size_t		offset = param - *sql;
+
+		*sql = pg_realloc(*sql, strlen(*sql) - len + valueln + 1);
+		param = *sql + offset;
+	}
+
+	if (valueln != len)
+		memmove(param + valueln, param + len, strlen(param + len) + 1);
+	memcpy(param, value, valueln);
+
+	return param + valueln;
+}
+
+static char *
+assignVariables(CState *st, char *sql)
+{
+	char	   *p,
+			   *name,
+			   *val;
+
+	p = sql;
+	while ((p = strchr(p, ':')) != NULL)
+	{
+		int			eaten;
+
+		name = parseVariable(p, &eaten);
+		if (name == NULL)
+		{
+			while (*p == ':')
+			{
+				p++;
+			}
+			continue;
+		}
+
+		val = getVariable(st, name);
+		free(name);
+		if (val == NULL)
+		{
+			p++;
+			continue;
+		}
+
+		p = replaceVariable(&sql, p, eaten, val);
+	}
+
+	return sql;
+}
+
+static void
+getQueryParams(CState *st, const Command *command, const char **params)
+{
+	int			i;
+
+	for (i = 0; i < command->argc - 1; i++)
+		params[i] = getVariable(st, command->argv[i + 1]);
+}
+
+static char *
+valueTypeName(PgBenchValue *pval)
+{
+	if (pval->type == PGBT_NO_VALUE)
+		return "none";
+	else if (pval->type == PGBT_NULL)
+		return "null";
+	else if (pval->type == PGBT_INT)
+		return "int";
+	else if (pval->type == PGBT_DOUBLE)
+		return "double";
+	else if (pval->type == PGBT_BOOLEAN)
+		return "boolean";
+	else
+	{
+		/* internal error, should never get there */
+		Assert(false);
+		return NULL;
+	}
+}
+
+/* get a value as a boolean, or tell if there is a problem */
+static bool
+coerceToBool(PgBenchValue *pval, bool *bval)
+{
+	if (pval->type == PGBT_BOOLEAN)
+	{
+		*bval = pval->u.bval;
+		return true;
+	}
+	else						/* NULL, INT or DOUBLE */
+	{
+		pg_log_error("cannot coerce %s to boolean", valueTypeName(pval));
+		*bval = false;			/* suppress uninitialized-variable warnings */
+		return false;
+	}
+}
+
+/*
+ * Return true or false from an expression for conditional purposes.
+ * Non zero numerical values are true, zero and NULL are false.
+ */
+static bool
+valueTruth(PgBenchValue *pval)
+{
+	switch (pval->type)
+	{
+		case PGBT_NULL:
+			return false;
+		case PGBT_BOOLEAN:
+			return pval->u.bval;
+		case PGBT_INT:
+			return pval->u.ival != 0;
+		case PGBT_DOUBLE:
+			return pval->u.dval != 0.0;
+		default:
+			/* internal error, unexpected type */
+			Assert(0);
+			return false;
+	}
+}
+
+/* get a value as an int, tell if there is a problem */
+static bool
+coerceToInt(PgBenchValue *pval, int64 *ival)
+{
+	if (pval->type == PGBT_INT)
+	{
+		*ival = pval->u.ival;
+		return true;
+	}
+	else if (pval->type == PGBT_DOUBLE)
+	{
+		double		dval = rint(pval->u.dval);
+
+		if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
+		{
+			pg_log_error("double to int overflow for %f", dval);
+			return false;
+		}
+		*ival = (int64) dval;
+		return true;
+	}
+	else						/* BOOLEAN or NULL */
+	{
+		pg_log_error("cannot coerce %s to int", valueTypeName(pval));
+		return false;
+	}
+}
+
+/* get a value as a double, or tell if there is a problem */
+static bool
+coerceToDouble(PgBenchValue *pval, double *dval)
+{
+	if (pval->type == PGBT_DOUBLE)
+	{
+		*dval = pval->u.dval;
+		return true;
+	}
+	else if (pval->type == PGBT_INT)
+	{
+		*dval = (double) pval->u.ival;
+		return true;
+	}
+	else						/* BOOLEAN or NULL */
+	{
+		pg_log_error("cannot coerce %s to double", valueTypeName(pval));
+		return false;
+	}
+}
+
+/* assign a null value */
+static void
+setNullValue(PgBenchValue *pv)
+{
+	pv->type = PGBT_NULL;
+	pv->u.ival = 0;
+}
+
+/* assign a boolean value */
+static void
+setBoolValue(PgBenchValue *pv, bool bval)
+{
+	pv->type = PGBT_BOOLEAN;
+	pv->u.bval = bval;
+}
+
+/* assign an integer value */
+static void
+setIntValue(PgBenchValue *pv, int64 ival)
+{
+	pv->type = PGBT_INT;
+	pv->u.ival = ival;
+}
+
+/* assign a double value */
+static void
+setDoubleValue(PgBenchValue *pv, double dval)
+{
+	pv->type = PGBT_DOUBLE;
+	pv->u.dval = dval;
+}
+
+static bool
+isLazyFunc(PgBenchFunction func)
+{
+	return func == PGBENCH_AND || func == PGBENCH_OR || func == PGBENCH_CASE;
+}
+
+/* lazy evaluation of some functions */
+static bool
+evalLazyFunc(CState *st,
+			 PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
+{
+	PgBenchValue a1,
+				a2;
+	bool		ba1,
+				ba2;
+
+	Assert(isLazyFunc(func) && args != NULL && args->next != NULL);
+
+	/* args points to first condition */
+	if (!evaluateExpr(st, args->expr, &a1))
+		return false;
+
+	/* second condition for AND/OR and corresponding branch for CASE */
+	args = args->next;
+
+	switch (func)
+	{
+		case PGBENCH_AND:
+			if (a1.type == PGBT_NULL)
+			{
+				setNullValue(retval);
+				return true;
+			}
+
+			if (!coerceToBool(&a1, &ba1))
+				return false;
+
+			if (!ba1)
+			{
+				setBoolValue(retval, false);
+				return true;
+			}
+
+			if (!evaluateExpr(st, args->expr, &a2))
+				return false;
+
+			if (a2.type == PGBT_NULL)
+			{
+				setNullValue(retval);
+				return true;
+			}
+			else if (!coerceToBool(&a2, &ba2))
+				return false;
+			else
+			{
+				setBoolValue(retval, ba2);
+				return true;
+			}
+
+			return true;
+
+		case PGBENCH_OR:
+
+			if (a1.type == PGBT_NULL)
+			{
+				setNullValue(retval);
+				return true;
+			}
+
+			if (!coerceToBool(&a1, &ba1))
+				return false;
+
+			if (ba1)
+			{
+				setBoolValue(retval, true);
+				return true;
+			}
+
+			if (!evaluateExpr(st, args->expr, &a2))
+				return false;
+
+			if (a2.type == PGBT_NULL)
+			{
+				setNullValue(retval);
+				return true;
+			}
+			else if (!coerceToBool(&a2, &ba2))
+				return false;
+			else
+			{
+				setBoolValue(retval, ba2);
+				return true;
+			}
+
+		case PGBENCH_CASE:
+			/* when true, execute branch */
+			if (valueTruth(&a1))
+				return evaluateExpr(st, args->expr, retval);
+
+			/* now args contains next condition or final else expression */
+			args = args->next;
+
+			/* final else case? */
+			if (args->next == NULL)
+				return evaluateExpr(st, args->expr, retval);
+
+			/* no, another when, proceed */
+			return evalLazyFunc(st, PGBENCH_CASE, args, retval);
+
+		default:
+			/* internal error, cannot get here */
+			Assert(0);
+			break;
+	}
+	return false;
+}
+
+/* maximum number of function arguments */
+#define MAX_FARGS 16
+
+/*
+ * Recursive evaluation of standard functions,
+ * which do not require lazy evaluation.
+ */
+static bool
+evalStandardFunc(CState *st,
+				 PgBenchFunction func, PgBenchExprLink *args,
+				 PgBenchValue *retval)
+{
+	/* evaluate all function arguments */
+	int			nargs = 0;
+	PgBenchValue vargs[MAX_FARGS];
+	PgBenchExprLink *l = args;
+	bool		has_null = false;
+
+	for (nargs = 0; nargs < MAX_FARGS && l != NULL; nargs++, l = l->next)
+	{
+		if (!evaluateExpr(st, l->expr, &vargs[nargs]))
+			return false;
+		has_null |= vargs[nargs].type == PGBT_NULL;
+	}
+
+	if (l != NULL)
+	{
+		pg_log_error("too many function arguments, maximum is %d", MAX_FARGS);
+		return false;
+	}
+
+	/* NULL arguments */
+	if (has_null && func != PGBENCH_IS && func != PGBENCH_DEBUG)
+	{
+		setNullValue(retval);
+		return true;
+	}
+
+	/* then evaluate function */
+	switch (func)
+	{
+			/* overloaded operators */
+		case PGBENCH_ADD:
+		case PGBENCH_SUB:
+		case PGBENCH_MUL:
+		case PGBENCH_DIV:
+		case PGBENCH_MOD:
+		case PGBENCH_EQ:
+		case PGBENCH_NE:
+		case PGBENCH_LE:
+		case PGBENCH_LT:
+			{
+				PgBenchValue *lval = &vargs[0],
+						   *rval = &vargs[1];
+
+				Assert(nargs == 2);
+
+				/* overloaded type management, double if some double */
+				if ((lval->type == PGBT_DOUBLE ||
+					 rval->type == PGBT_DOUBLE) && func != PGBENCH_MOD)
+				{
+					double		ld,
+								rd;
+
+					if (!coerceToDouble(lval, &ld) ||
+						!coerceToDouble(rval, &rd))
+						return false;
+
+					switch (func)
+					{
+						case PGBENCH_ADD:
+							setDoubleValue(retval, ld + rd);
+							return true;
+
+						case PGBENCH_SUB:
+							setDoubleValue(retval, ld - rd);
+							return true;
+
+						case PGBENCH_MUL:
+							setDoubleValue(retval, ld * rd);
+							return true;
+
+						case PGBENCH_DIV:
+							setDoubleValue(retval, ld / rd);
+							return true;
+
+						case PGBENCH_EQ:
+							setBoolValue(retval, ld == rd);
+							return true;
+
+						case PGBENCH_NE:
+							setBoolValue(retval, ld != rd);
+							return true;
+
+						case PGBENCH_LE:
+							setBoolValue(retval, ld <= rd);
+							return true;
+
+						case PGBENCH_LT:
+							setBoolValue(retval, ld < rd);
+							return true;
+
+						default:
+							/* cannot get here */
+							Assert(0);
+					}
+				}
+				else			/* we have integer operands, or % */
+				{
+					int64		li,
+								ri,
+								res;
+
+					if (!coerceToInt(lval, &li) ||
+						!coerceToInt(rval, &ri))
+						return false;
+
+					switch (func)
+					{
+						case PGBENCH_ADD:
+							if (pg_add_s64_overflow(li, ri, &res))
+							{
+								pg_log_error("bigint add out of range");
+								return false;
+							}
+							setIntValue(retval, res);
+							return true;
+
+						case PGBENCH_SUB:
+							if (pg_sub_s64_overflow(li, ri, &res))
+							{
+								pg_log_error("bigint sub out of range");
+								return false;
+							}
+							setIntValue(retval, res);
+							return true;
+
+						case PGBENCH_MUL:
+							if (pg_mul_s64_overflow(li, ri, &res))
+							{
+								pg_log_error("bigint mul out of range");
+								return false;
+							}
+							setIntValue(retval, res);
+							return true;
+
+						case PGBENCH_EQ:
+							setBoolValue(retval, li == ri);
+							return true;
+
+						case PGBENCH_NE:
+							setBoolValue(retval, li != ri);
+							return true;
+
+						case PGBENCH_LE:
+							setBoolValue(retval, li <= ri);
+							return true;
+
+						case PGBENCH_LT:
+							setBoolValue(retval, li < ri);
+							return true;
+
+						case PGBENCH_DIV:
+						case PGBENCH_MOD:
+							if (ri == 0)
+							{
+								pg_log_error("division by zero");
+								return false;
+							}
+							/* special handling of -1 divisor */
+							if (ri == -1)
+							{
+								if (func == PGBENCH_DIV)
+								{
+									/* overflow check (needed for INT64_MIN) */
+									if (li == PG_INT64_MIN)
+									{
+										pg_log_error("bigint div out of range");
+										return false;
+									}
+									else
+										setIntValue(retval, -li);
+								}
+								else
+									setIntValue(retval, 0);
+								return true;
+							}
+							/* else divisor is not -1 */
+							if (func == PGBENCH_DIV)
+								setIntValue(retval, li / ri);
+							else	/* func == PGBENCH_MOD */
+								setIntValue(retval, li % ri);
+
+							return true;
+
+						default:
+							/* cannot get here */
+							Assert(0);
+					}
+				}
+
+				Assert(0);
+				return false;	/* NOTREACHED */
+			}
+
+			/* integer bitwise operators */
+		case PGBENCH_BITAND:
+		case PGBENCH_BITOR:
+		case PGBENCH_BITXOR:
+		case PGBENCH_LSHIFT:
+		case PGBENCH_RSHIFT:
+			{
+				int64		li,
+							ri;
+
+				if (!coerceToInt(&vargs[0], &li) || !coerceToInt(&vargs[1], &ri))
+					return false;
+
+				if (func == PGBENCH_BITAND)
+					setIntValue(retval, li & ri);
+				else if (func == PGBENCH_BITOR)
+					setIntValue(retval, li | ri);
+				else if (func == PGBENCH_BITXOR)
+					setIntValue(retval, li ^ ri);
+				else if (func == PGBENCH_LSHIFT)
+					setIntValue(retval, li << ri);
+				else if (func == PGBENCH_RSHIFT)
+					setIntValue(retval, li >> ri);
+				else			/* cannot get here */
+					Assert(0);
+
+				return true;
+			}
+
+			/* logical operators */
+		case PGBENCH_NOT:
+			{
+				bool		b;
+
+				if (!coerceToBool(&vargs[0], &b))
+					return false;
+
+				setBoolValue(retval, !b);
+				return true;
+			}
+
+			/* no arguments */
+		case PGBENCH_PI:
+			setDoubleValue(retval, M_PI);
+			return true;
+
+			/* 1 overloaded argument */
+		case PGBENCH_ABS:
+			{
+				PgBenchValue *varg = &vargs[0];
+
+				Assert(nargs == 1);
+
+				if (varg->type == PGBT_INT)
+				{
+					int64		i = varg->u.ival;
+
+					setIntValue(retval, i < 0 ? -i : i);
+				}
+				else
+				{
+					double		d = varg->u.dval;
+
+					Assert(varg->type == PGBT_DOUBLE);
+					setDoubleValue(retval, d < 0.0 ? -d : d);
+				}
+
+				return true;
+			}
+
+		case PGBENCH_DEBUG:
+			{
+				PgBenchValue *varg = &vargs[0];
+
+				Assert(nargs == 1);
+
+				fprintf(stderr, "debug(script=%d,command=%d): ",
+						st->use_file, st->command + 1);
+
+				if (varg->type == PGBT_NULL)
+					fprintf(stderr, "null\n");
+				else if (varg->type == PGBT_BOOLEAN)
+					fprintf(stderr, "boolean %s\n", varg->u.bval ? "true" : "false");
+				else if (varg->type == PGBT_INT)
+					fprintf(stderr, "int " INT64_FORMAT "\n", varg->u.ival);
+				else if (varg->type == PGBT_DOUBLE)
+					fprintf(stderr, "double %.*g\n", DBL_DIG, varg->u.dval);
+				else			/* internal error, unexpected type */
+					Assert(0);
+
+				*retval = *varg;
+
+				return true;
+			}
+
+			/* 1 double argument */
+		case PGBENCH_DOUBLE:
+		case PGBENCH_SQRT:
+		case PGBENCH_LN:
+		case PGBENCH_EXP:
+			{
+				double		dval;
+
+				Assert(nargs == 1);
+
+				if (!coerceToDouble(&vargs[0], &dval))
+					return false;
+
+				if (func == PGBENCH_SQRT)
+					dval = sqrt(dval);
+				else if (func == PGBENCH_LN)
+					dval = log(dval);
+				else if (func == PGBENCH_EXP)
+					dval = exp(dval);
+				/* else is cast: do nothing */
+
+				setDoubleValue(retval, dval);
+				return true;
+			}
+
+			/* 1 int argument */
+		case PGBENCH_INT:
+			{
+				int64		ival;
+
+				Assert(nargs == 1);
+
+				if (!coerceToInt(&vargs[0], &ival))
+					return false;
+
+				setIntValue(retval, ival);
+				return true;
+			}
+
+			/* variable number of arguments */
+		case PGBENCH_LEAST:
+		case PGBENCH_GREATEST:
+			{
+				bool		havedouble;
+				int			i;
+
+				Assert(nargs >= 1);
+
+				/* need double result if any input is double */
+				havedouble = false;
+				for (i = 0; i < nargs; i++)
+				{
+					if (vargs[i].type == PGBT_DOUBLE)
+					{
+						havedouble = true;
+						break;
+					}
+				}
+				if (havedouble)
+				{
+					double		extremum;
+
+					if (!coerceToDouble(&vargs[0], &extremum))
+						return false;
+					for (i = 1; i < nargs; i++)
+					{
+						double		dval;
+
+						if (!coerceToDouble(&vargs[i], &dval))
+							return false;
+						if (func == PGBENCH_LEAST)
+							extremum = Min(extremum, dval);
+						else
+							extremum = Max(extremum, dval);
+					}
+					setDoubleValue(retval, extremum);
+				}
+				else
+				{
+					int64		extremum;
+
+					if (!coerceToInt(&vargs[0], &extremum))
+						return false;
+					for (i = 1; i < nargs; i++)
+					{
+						int64		ival;
+
+						if (!coerceToInt(&vargs[i], &ival))
+							return false;
+						if (func == PGBENCH_LEAST)
+							extremum = Min(extremum, ival);
+						else
+							extremum = Max(extremum, ival);
+					}
+					setIntValue(retval, extremum);
+				}
+				return true;
+			}
+
+			/* random functions */
+		case PGBENCH_RANDOM:
+		case PGBENCH_RANDOM_EXPONENTIAL:
+		case PGBENCH_RANDOM_GAUSSIAN:
+		case PGBENCH_RANDOM_ZIPFIAN:
+			{
+				int64		imin,
+							imax,
+							delta;
+
+				Assert(nargs >= 2);
+
+				if (!coerceToInt(&vargs[0], &imin) ||
+					!coerceToInt(&vargs[1], &imax))
+					return false;
+
+				/* check random range */
+				if (unlikely(imin > imax))
+				{
+					pg_log_error("empty range given to random");
+					return false;
+				}
+				else if (unlikely(pg_sub_s64_overflow(imax, imin, &delta) ||
+								  pg_add_s64_overflow(delta, 1, &delta)))
+				{
+					/* prevent int overflows in random functions */
+					pg_log_error("random range is too large");
+					return false;
+				}
+
+				if (func == PGBENCH_RANDOM)
+				{
+					Assert(nargs == 2);
+					setIntValue(retval, getrand(&st->cs_func_rs, imin, imax));
+				}
+				else			/* gaussian & exponential */
+				{
+					double		param;
+
+					Assert(nargs == 3);
+
+					if (!coerceToDouble(&vargs[2], &param))
+						return false;
+
+					if (func == PGBENCH_RANDOM_GAUSSIAN)
+					{
+						if (param < MIN_GAUSSIAN_PARAM)
+						{
+							pg_log_error("gaussian parameter must be at least %f (not %f)",
+										 MIN_GAUSSIAN_PARAM, param);
+							return false;
+						}
+
+						setIntValue(retval,
+									getGaussianRand(&st->cs_func_rs,
+													imin, imax, param));
+					}
+					else if (func == PGBENCH_RANDOM_ZIPFIAN)
+					{
+						if (param < MIN_ZIPFIAN_PARAM || param > MAX_ZIPFIAN_PARAM)
+						{
+							pg_log_error("zipfian parameter must be in range [%.3f, %.0f] (not %f)",
+										 MIN_ZIPFIAN_PARAM, MAX_ZIPFIAN_PARAM, param);
+							return false;
+						}
+
+						setIntValue(retval,
+									getZipfianRand(&st->cs_func_rs, imin, imax, param));
+					}
+					else		/* exponential */
+					{
+						if (param <= 0.0)
+						{
+							pg_log_error("exponential parameter must be greater than zero (not %f)",
+										 param);
+							return false;
+						}
+
+						setIntValue(retval,
+									getExponentialRand(&st->cs_func_rs,
+													   imin, imax, param));
+					}
+				}
+
+				return true;
+			}
+
+		case PGBENCH_POW:
+			{
+				PgBenchValue *lval = &vargs[0];
+				PgBenchValue *rval = &vargs[1];
+				double		ld,
+							rd;
+
+				Assert(nargs == 2);
+
+				if (!coerceToDouble(lval, &ld) ||
+					!coerceToDouble(rval, &rd))
+					return false;
+
+				setDoubleValue(retval, pow(ld, rd));
+
+				return true;
+			}
+
+		case PGBENCH_IS:
+			{
+				Assert(nargs == 2);
+
+				/*
+				 * note: this simple implementation is more permissive than
+				 * SQL
+				 */
+				setBoolValue(retval,
+							 vargs[0].type == vargs[1].type &&
+							 vargs[0].u.bval == vargs[1].u.bval);
+				return true;
+			}
+
+			/* hashing */
+		case PGBENCH_HASH_FNV1A:
+		case PGBENCH_HASH_MURMUR2:
+			{
+				int64		val,
+							seed;
+
+				Assert(nargs == 2);
+
+				if (!coerceToInt(&vargs[0], &val) ||
+					!coerceToInt(&vargs[1], &seed))
+					return false;
+
+				if (func == PGBENCH_HASH_MURMUR2)
+					setIntValue(retval, getHashMurmur2(val, seed));
+				else if (func == PGBENCH_HASH_FNV1A)
+					setIntValue(retval, getHashFnv1a(val, seed));
+				else
+					/* cannot get here */
+					Assert(0);
+
+				return true;
+			}
+
+		case PGBENCH_PERMUTE:
+			{
+				int64		val,
+							size,
+							seed;
+
+				Assert(nargs == 3);
+
+				if (!coerceToInt(&vargs[0], &val) ||
+					!coerceToInt(&vargs[1], &size) ||
+					!coerceToInt(&vargs[2], &seed))
+					return false;
+
+				if (size <= 0)
+				{
+					pg_log_error("permute size parameter must be greater than zero");
+					return false;
+				}
+
+				setIntValue(retval, permute(val, size, seed));
+				return true;
+			}
+
+		default:
+			/* cannot get here */
+			Assert(0);
+			/* dead code to avoid a compiler warning */
+			return false;
+	}
+}
+
+/* evaluate some function */
+static bool
+evalFunc(CState *st,
+		 PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
+{
+	if (isLazyFunc(func))
+		return evalLazyFunc(st, func, args, retval);
+	else
+		return evalStandardFunc(st, func, args, retval);
+}
+
+/*
+ * Recursive evaluation of an expression in a pgbench script
+ * using the current state of variables.
+ * Returns whether the evaluation was ok,
+ * the value itself is returned through the retval pointer.
+ */
+static bool
+evaluateExpr(CState *st, PgBenchExpr *expr, PgBenchValue *retval)
+{
+	switch (expr->etype)
+	{
+		case ENODE_CONSTANT:
+			{
+				*retval = expr->u.constant;
+				return true;
+			}
+
+		case ENODE_VARIABLE:
+			{
+				Variable   *var;
+
+				if ((var = lookupVariable(st, expr->u.variable.varname)) == NULL)
+				{
+					pg_log_error("undefined variable \"%s\"", expr->u.variable.varname);
+					return false;
+				}
+
+				if (!makeVariableValue(var))
+					return false;
+
+				*retval = var->value;
+				return true;
+			}
+
+		case ENODE_FUNCTION:
+			return evalFunc(st,
+							expr->u.function.function,
+							expr->u.function.args,
+							retval);
+
+		default:
+			/* internal error which should never occur */
+			pg_log_fatal("unexpected enode type in evaluation: %d", expr->etype);
+			exit(1);
+	}
+}
+
+/*
+ * Convert command name to meta-command enum identifier
+ */
+static MetaCommand
+getMetaCommand(const char *cmd)
+{
+	MetaCommand mc;
+
+	if (cmd == NULL)
+		mc = META_NONE;
+	else if (pg_strcasecmp(cmd, "set") == 0)
+		mc = META_SET;
+	else if (pg_strcasecmp(cmd, "setshell") == 0)
+		mc = META_SETSHELL;
+	else if (pg_strcasecmp(cmd, "shell") == 0)
+		mc = META_SHELL;
+	else if (pg_strcasecmp(cmd, "sleep") == 0)
+		mc = META_SLEEP;
+	else if (pg_strcasecmp(cmd, "if") == 0)
+		mc = META_IF;
+	else if (pg_strcasecmp(cmd, "elif") == 0)
+		mc = META_ELIF;
+	else if (pg_strcasecmp(cmd, "else") == 0)
+		mc = META_ELSE;
+	else if (pg_strcasecmp(cmd, "endif") == 0)
+		mc = META_ENDIF;
+	else if (pg_strcasecmp(cmd, "gset") == 0)
+		mc = META_GSET;
+	else if (pg_strcasecmp(cmd, "aset") == 0)
+		mc = META_ASET;
+	else if (pg_strcasecmp(cmd, "startpipeline") == 0)
+		mc = META_STARTPIPELINE;
+	else if (pg_strcasecmp(cmd, "endpipeline") == 0)
+		mc = META_ENDPIPELINE;
+	else
+		mc = META_NONE;
+	return mc;
+}
+
+/*
+ * Run a shell command. The result is assigned to the variable if not NULL.
+ * Return true if succeeded, or false on error.
+ */
+static bool
+runShellCommand(CState *st, char *variable, char **argv, int argc)
+{
+	char		command[SHELL_COMMAND_SIZE];
+	int			i,
+				len = 0;
+	FILE	   *fp;
+	char		res[64];
+	char	   *endptr;
+	int			retval;
+
+	/*----------
+	 * Join arguments with whitespace separators. Arguments starting with
+	 * exactly one colon are treated as variables:
+	 *	name - append a string "name"
+	 *	:var - append a variable named 'var'
+	 *	::name - append a string ":name"
+	 *----------
+	 */
+	for (i = 0; i < argc; i++)
+	{
+		char	   *arg;
+		int			arglen;
+
+		if (argv[i][0] != ':')
+		{
+			arg = argv[i];		/* a string literal */
+		}
+		else if (argv[i][1] == ':')
+		{
+			arg = argv[i] + 1;	/* a string literal starting with colons */
+		}
+		else if ((arg = getVariable(st, argv[i] + 1)) == NULL)
+		{
+			pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[i]);
+			return false;
+		}
+
+		arglen = strlen(arg);
+		if (len + arglen + (i > 0 ? 1 : 0) >= SHELL_COMMAND_SIZE - 1)
+		{
+			pg_log_error("%s: shell command is too long", argv[0]);
+			return false;
+		}
+
+		if (i > 0)
+			command[len++] = ' ';
+		memcpy(command + len, arg, arglen);
+		len += arglen;
+	}
+
+	command[len] = '\0';
+
+	/* Fast path for non-assignment case */
+	if (variable == NULL)
+	{
+		if (system(command))
+		{
+			if (!timer_exceeded)
+				pg_log_error("%s: could not launch shell command", argv[0]);
+			return false;
+		}
+		return true;
+	}
+
+	/* Execute the command with pipe and read the standard output. */
+	if ((fp = popen(command, "r")) == NULL)
+	{
+		pg_log_error("%s: could not launch shell command", argv[0]);
+		return false;
+	}
+	if (fgets(res, sizeof(res), fp) == NULL)
+	{
+		if (!timer_exceeded)
+			pg_log_error("%s: could not read result of shell command", argv[0]);
+		(void) pclose(fp);
+		return false;
+	}
+	if (pclose(fp) < 0)
+	{
+		pg_log_error("%s: could not close shell command", argv[0]);
+		return false;
+	}
+
+	/* Check whether the result is an integer and assign it to the variable */
+	retval = (int) strtol(res, &endptr, 10);
+	while (*endptr != '\0' && isspace((unsigned char) *endptr))
+		endptr++;
+	if (*res == '\0' || *endptr != '\0')
+	{
+		pg_log_error("%s: shell command must return an integer (not \"%s\")", argv[0], res);
+		return false;
+	}
+	if (!putVariableInt(st, "setshell", variable, retval))
+		return false;
+
+	pg_log_debug("%s: shell parameter name: \"%s\", value: \"%s\"", argv[0], argv[1], res);
+
+	return true;
+}
+
+#define MAX_PREPARE_NAME		32
+static void
+preparedStatementName(char *buffer, int file, int state)
+{
+	sprintf(buffer, "P%d_%d", file, state);
+}
+
+static void
+commandFailed(CState *st, const char *cmd, const char *message)
+{
+	pg_log_error("client %d aborted in command %d (%s) of script %d; %s",
+				 st->id, st->command, cmd, st->use_file, message);
+}
+
+/* return a script number with a weighted choice. */
+static int
+chooseScript(TState *thread)
+{
+	int			i = 0;
+	int64		w;
+
+	if (num_scripts == 1)
+		return 0;
+
+	w = getrand(&thread->ts_choose_rs, 0, total_weight - 1);
+	do
+	{
+		w -= sql_script[i++].weight;
+	} while (w >= 0);
+
+	return i - 1;
+}
+
+/* Send a SQL command, using the chosen querymode */
+static bool
+sendCommand(CState *st, Command *command)
+{
+	int			r;
+
+	if (querymode == QUERY_SIMPLE)
+	{
+		char	   *sql;
+
+		sql = pg_strdup(command->argv[0]);
+		sql = assignVariables(st, sql);
+
+		pg_log_debug("client %d sending %s", st->id, sql);
+		r = PQsendQuery(st->con, sql);
+		free(sql);
+	}
+	else if (querymode == QUERY_EXTENDED)
+	{
+		const char *sql = command->argv[0];
+		const char *params[MAX_ARGS];
+
+		getQueryParams(st, command, params);
+
+		pg_log_debug("client %d sending %s", st->id, sql);
+		r = PQsendQueryParams(st->con, sql, command->argc - 1,
+							  NULL, params, NULL, NULL, 0);
+	}
+	else if (querymode == QUERY_PREPARED)
+	{
+		char		name[MAX_PREPARE_NAME];
+		const char *params[MAX_ARGS];
+
+		if (!st->prepared[st->use_file])
+		{
+			int			j;
+			Command   **commands = sql_script[st->use_file].commands;
+
+			for (j = 0; commands[j] != NULL; j++)
+			{
+				PGresult   *res;
+				char		name[MAX_PREPARE_NAME];
+
+				if (commands[j]->type != SQL_COMMAND)
+					continue;
+				preparedStatementName(name, st->use_file, j);
+				if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
+				{
+					res = PQprepare(st->con, name,
+									commands[j]->argv[0], commands[j]->argc - 1, NULL);
+					if (PQresultStatus(res) != PGRES_COMMAND_OK)
+						pg_log_error("%s", PQerrorMessage(st->con));
+					PQclear(res);
+				}
+				else
+				{
+					/*
+					 * In pipeline mode, we use asynchronous functions. If a
+					 * server-side error occurs, it will be processed later
+					 * among the other results.
+					 */
+					if (!PQsendPrepare(st->con, name,
+									   commands[j]->argv[0], commands[j]->argc - 1, NULL))
+						pg_log_error("%s", PQerrorMessage(st->con));
+				}
+			}
+			st->prepared[st->use_file] = true;
+		}
+
+		getQueryParams(st, command, params);
+		preparedStatementName(name, st->use_file, st->command);
+
+		pg_log_debug("client %d sending %s", st->id, name);
+		r = PQsendQueryPrepared(st->con, name, command->argc - 1,
+								params, NULL, NULL, 0);
+	}
+	else						/* unknown sql mode */
+		r = 0;
+
+	if (r == 0)
+	{
+		pg_log_debug("client %d could not send %s", st->id, command->argv[0]);
+		return false;
+	}
+	else
+		return true;
+}
+
+/*
+ * Process query response from the backend.
+ *
+ * If varprefix is not NULL, it's the variable name prefix where to store
+ * the results of the *last* command (META_GSET) or *all* commands
+ * (META_ASET).
+ *
+ * Returns true if everything is A-OK, false if any error occurs.
+ */
+static bool
+readCommandResponse(CState *st, MetaCommand meta, char *varprefix)
+{
+	PGresult   *res;
+	PGresult   *next_res;
+	int			qrynum = 0;
+
+	/*
+	 * varprefix should be set only with \gset or \aset, and \endpipeline and
+	 * SQL commands do not need it.
+	 */
+	Assert((meta == META_NONE && varprefix == NULL) ||
+		   ((meta == META_ENDPIPELINE) && varprefix == NULL) ||
+		   ((meta == META_GSET || meta == META_ASET) && varprefix != NULL));
+
+	res = PQgetResult(st->con);
+
+	while (res != NULL)
+	{
+		bool		is_last;
+
+		/* peek at the next result to know whether the current is last */
+		next_res = PQgetResult(st->con);
+		is_last = (next_res == NULL);
+
+		switch (PQresultStatus(res))
+		{
+			case PGRES_COMMAND_OK:	/* non-SELECT commands */
+			case PGRES_EMPTY_QUERY: /* may be used for testing no-op overhead */
+				if (is_last && meta == META_GSET)
+				{
+					pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
+								 st->id, st->use_file, st->command, qrynum, 0);
+					goto error;
+				}
+				break;
+
+			case PGRES_TUPLES_OK:
+				if ((is_last && meta == META_GSET) || meta == META_ASET)
+				{
+					int			ntuples = PQntuples(res);
+
+					if (meta == META_GSET && ntuples != 1)
+					{
+						/* under \gset, report the error */
+						pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
+									 st->id, st->use_file, st->command, qrynum, PQntuples(res));
+						goto error;
+					}
+					else if (meta == META_ASET && ntuples <= 0)
+					{
+						/* coldly skip empty result under \aset */
+						break;
+					}
+
+					/* store results into variables */
+					for (int fld = 0; fld < PQnfields(res); fld++)
+					{
+						char	   *varname = PQfname(res, fld);
+
+						/* allocate varname only if necessary, freed below */
+						if (*varprefix != '\0')
+							varname = psprintf("%s%s", varprefix, varname);
+
+						/* store last row result as a string */
+						if (!putVariable(st, meta == META_ASET ? "aset" : "gset", varname,
+										 PQgetvalue(res, ntuples - 1, fld)))
+						{
+							/* internal error */
+							pg_log_error("client %d script %d command %d query %d: error storing into variable %s",
+										 st->id, st->use_file, st->command, qrynum, varname);
+							goto error;
+						}
+
+						if (*varprefix != '\0')
+							pg_free(varname);
+					}
+				}
+				/* otherwise the result is simply thrown away by PQclear below */
+				break;
+
+			case PGRES_PIPELINE_SYNC:
+				pg_log_debug("client %d pipeline ending", st->id);
+				if (PQexitPipelineMode(st->con) != 1)
+					pg_log_error("client %d failed to exit pipeline mode: %s", st->id,
+								 PQerrorMessage(st->con));
+				break;
+
+			default:
+				/* anything else is unexpected */
+				pg_log_error("client %d script %d aborted in command %d query %d: %s",
+							 st->id, st->use_file, st->command, qrynum,
+							 PQerrorMessage(st->con));
+				goto error;
+		}
+
+		PQclear(res);
+		qrynum++;
+		res = next_res;
+	}
+
+	if (qrynum == 0)
+	{
+		pg_log_error("client %d command %d: no results", st->id, st->command);
+		return false;
+	}
+
+	return true;
+
+error:
+	PQclear(res);
+	PQclear(next_res);
+	do
+	{
+		res = PQgetResult(st->con);
+		PQclear(res);
+	} while (res);
+
+	return false;
+}
+
+/*
+ * Parse the argument to a \sleep command, and return the requested amount
+ * of delay, in microseconds.  Returns true on success, false on error.
+ */
+static bool
+evaluateSleep(CState *st, int argc, char **argv, int *usecs)
+{
+	char	   *var;
+	int			usec;
+
+	if (*argv[1] == ':')
+	{
+		if ((var = getVariable(st, argv[1] + 1)) == NULL)
+		{
+			pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[1] + 1);
+			return false;
+		}
+
+		usec = atoi(var);
+
+		/* Raise an error if the value of a variable is not a number */
+		if (usec == 0 && !isdigit((unsigned char) *var))
+		{
+			pg_log_error("%s: invalid sleep time \"%s\" for variable \"%s\"",
+						 argv[0], var, argv[1] + 1);
+			return false;
+		}
+	}
+	else
+		usec = atoi(argv[1]);
+
+	if (argc > 2)
+	{
+		if (pg_strcasecmp(argv[2], "ms") == 0)
+			usec *= 1000;
+		else if (pg_strcasecmp(argv[2], "s") == 0)
+			usec *= 1000000;
+	}
+	else
+		usec *= 1000000;
+
+	*usecs = usec;
+	return true;
+}
+
+/*
+ * Advance the state machine of a connection.
+ */
+static void
+advanceConnectionState(TState *thread, CState *st, StatsData *agg)
+{
+
+	/*
+	 * gettimeofday() isn't free, so we get the current timestamp lazily the
+	 * first time it's needed, and reuse the same value throughout this
+	 * function after that.  This also ensures that e.g. the calculated
+	 * latency reported in the log file and in the totals are the same. Zero
+	 * means "not set yet".  Reset "now" when we execute shell commands or
+	 * expressions, which might take a non-negligible amount of time, though.
+	 */
+	pg_time_usec_t now = 0;
+
+	/*
+	 * Loop in the state machine, until we have to wait for a result from the
+	 * server or have to sleep for throttling or \sleep.
+	 *
+	 * Note: In the switch-statement below, 'break' will loop back here,
+	 * meaning "continue in the state machine".  Return is used to return to
+	 * the caller, giving the thread the opportunity to advance another
+	 * client.
+	 */
+	for (;;)
+	{
+		Command    *command;
+
+		switch (st->state)
+		{
+				/* Select transaction (script) to run.  */
+			case CSTATE_CHOOSE_SCRIPT:
+				st->use_file = chooseScript(thread);
+				Assert(conditional_stack_empty(st->cstack));
+
+				pg_log_debug("client %d executing script \"%s\"",
+							 st->id, sql_script[st->use_file].desc);
+
+				/*
+				 * If time is over, we're done; otherwise, get ready to start
+				 * a new transaction, or to get throttled if that's requested.
+				 */
+				st->state = timer_exceeded ? CSTATE_FINISHED :
+					throttle_delay > 0 ? CSTATE_PREPARE_THROTTLE : CSTATE_START_TX;
+				break;
+
+				/* Start new transaction (script) */
+			case CSTATE_START_TX:
+				pg_time_now_lazy(&now);
+
+				/* establish connection if needed, i.e. under --connect */
+				if (st->con == NULL)
+				{
+					pg_time_usec_t start = now;
+
+					if ((st->con = doConnect()) == NULL)
+					{
+						pg_log_error("client %d aborted while establishing connection", st->id);
+						st->state = CSTATE_ABORTED;
+						break;
+					}
+
+					/* reset now after connection */
+					now = pg_time_now();
+
+					thread->conn_duration += now - start;
+
+					/* Reset session-local state */
+					memset(st->prepared, 0, sizeof(st->prepared));
+				}
+
+				/* record transaction start time */
+				st->txn_begin = now;
+
+				/*
+				 * When not throttling, this is also the transaction's
+				 * scheduled start time.
+				 */
+				if (!throttle_delay)
+					st->txn_scheduled = now;
+
+				/* Begin with the first command */
+				st->state = CSTATE_START_COMMAND;
+				st->command = 0;
+				break;
+
+				/*
+				 * Handle throttling once per transaction by sleeping.
+				 */
+			case CSTATE_PREPARE_THROTTLE:
+
+				/*
+				 * Generate a delay such that the series of delays will
+				 * approximate a Poisson distribution centered on the
+				 * throttle_delay time.
+				 *
+				 * If transactions are too slow or a given wait is shorter
+				 * than a transaction, the next transaction will start right
+				 * away.
+				 */
+				Assert(throttle_delay > 0);
+
+				thread->throttle_trigger +=
+					getPoissonRand(&thread->ts_throttle_rs, throttle_delay);
+				st->txn_scheduled = thread->throttle_trigger;
+
+				/*
+				 * If --latency-limit is used, and this slot is already late
+				 * so that the transaction will miss the latency limit even if
+				 * it completed immediately, skip this time slot and loop to
+				 * reschedule.
+				 */
+				if (latency_limit)
+				{
+					pg_time_now_lazy(&now);
+
+					if (thread->throttle_trigger < now - latency_limit)
+					{
+						processXactStats(thread, st, &now, true, agg);
+
+						/*
+						 * Finish client if -T or -t was exceeded.
+						 *
+						 * Stop counting skipped transactions under -T as soon
+						 * as the timer is exceeded. Because otherwise it can
+						 * take a very long time to count all of them
+						 * especially when quite a lot of them happen with
+						 * unrealistically high rate setting in -R, which
+						 * would prevent pgbench from ending immediately.
+						 * Because of this behavior, note that there is no
+						 * guarantee that all skipped transactions are counted
+						 * under -T though there is under -t. This is OK in
+						 * practice because it's very unlikely to happen with
+						 * realistic setting.
+						 */
+						if (timer_exceeded || (nxacts > 0 && st->cnt >= nxacts))
+							st->state = CSTATE_FINISHED;
+
+						/* Go back to top of loop with CSTATE_PREPARE_THROTTLE */
+						break;
+					}
+				}
+
+				/*
+				 * stop client if next transaction is beyond pgbench end of
+				 * execution; otherwise, throttle it.
+				 */
+				st->state = end_time > 0 && st->txn_scheduled > end_time ?
+					CSTATE_FINISHED : CSTATE_THROTTLE;
+				break;
+
+				/*
+				 * Wait until it's time to start next transaction.
+				 */
+			case CSTATE_THROTTLE:
+				pg_time_now_lazy(&now);
+
+				if (now < st->txn_scheduled)
+					return;		/* still sleeping, nothing to do here */
+
+				/* done sleeping, but don't start transaction if we're done */
+				st->state = timer_exceeded ? CSTATE_FINISHED : CSTATE_START_TX;
+				break;
+
+				/*
+				 * Send a command to server (or execute a meta-command)
+				 */
+			case CSTATE_START_COMMAND:
+				command = sql_script[st->use_file].commands[st->command];
+
+				/* Transition to script end processing if done */
+				if (command == NULL)
+				{
+					st->state = CSTATE_END_TX;
+					break;
+				}
+
+				/* record begin time of next command, and initiate it */
+				if (report_per_command)
+				{
+					pg_time_now_lazy(&now);
+					st->stmt_begin = now;
+				}
+
+				/* Execute the command */
+				if (command->type == SQL_COMMAND)
+				{
+					/* disallow \aset and \gset in pipeline mode */
+					if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
+					{
+						if (command->meta == META_GSET)
+						{
+							commandFailed(st, "gset", "\\gset is not allowed in pipeline mode");
+							st->state = CSTATE_ABORTED;
+							break;
+						}
+						else if (command->meta == META_ASET)
+						{
+							commandFailed(st, "aset", "\\aset is not allowed in pipeline mode");
+							st->state = CSTATE_ABORTED;
+							break;
+						}
+					}
+
+					if (!sendCommand(st, command))
+					{
+						commandFailed(st, "SQL", "SQL command send failed");
+						st->state = CSTATE_ABORTED;
+					}
+					else
+					{
+						/* Wait for results, unless in pipeline mode */
+						if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
+							st->state = CSTATE_WAIT_RESULT;
+						else
+							st->state = CSTATE_END_COMMAND;
+					}
+				}
+				else if (command->type == META_COMMAND)
+				{
+					/*-----
+					 * Possible state changes when executing meta commands:
+					 * - on errors CSTATE_ABORTED
+					 * - on sleep CSTATE_SLEEP
+					 * - else CSTATE_END_COMMAND
+					 */
+					st->state = executeMetaCommand(st, &now);
+				}
+
+				/*
+				 * We're now waiting for an SQL command to complete, or
+				 * finished processing a metacommand, or need to sleep, or
+				 * something bad happened.
+				 */
+				Assert(st->state == CSTATE_WAIT_RESULT ||
+					   st->state == CSTATE_END_COMMAND ||
+					   st->state == CSTATE_SLEEP ||
+					   st->state == CSTATE_ABORTED);
+				break;
+
+				/*
+				 * non executed conditional branch
+				 */
+			case CSTATE_SKIP_COMMAND:
+				Assert(!conditional_active(st->cstack));
+				/* quickly skip commands until something to do... */
+				while (true)
+				{
+					Command    *command;
+
+					command = sql_script[st->use_file].commands[st->command];
+
+					/* cannot reach end of script in that state */
+					Assert(command != NULL);
+
+					/*
+					 * if this is conditional related, update conditional
+					 * state
+					 */
+					if (command->type == META_COMMAND &&
+						(command->meta == META_IF ||
+						 command->meta == META_ELIF ||
+						 command->meta == META_ELSE ||
+						 command->meta == META_ENDIF))
+					{
+						switch (conditional_stack_peek(st->cstack))
+						{
+							case IFSTATE_FALSE:
+								if (command->meta == META_IF ||
+									command->meta == META_ELIF)
+								{
+									/* we must evaluate the condition */
+									st->state = CSTATE_START_COMMAND;
+								}
+								else if (command->meta == META_ELSE)
+								{
+									/* we must execute next command */
+									conditional_stack_poke(st->cstack,
+														   IFSTATE_ELSE_TRUE);
+									st->state = CSTATE_START_COMMAND;
+									st->command++;
+								}
+								else if (command->meta == META_ENDIF)
+								{
+									Assert(!conditional_stack_empty(st->cstack));
+									conditional_stack_pop(st->cstack);
+									if (conditional_active(st->cstack))
+										st->state = CSTATE_START_COMMAND;
+
+									/*
+									 * else state remains in
+									 * CSTATE_SKIP_COMMAND
+									 */
+									st->command++;
+								}
+								break;
+
+							case IFSTATE_IGNORED:
+							case IFSTATE_ELSE_FALSE:
+								if (command->meta == META_IF)
+									conditional_stack_push(st->cstack,
+														   IFSTATE_IGNORED);
+								else if (command->meta == META_ENDIF)
+								{
+									Assert(!conditional_stack_empty(st->cstack));
+									conditional_stack_pop(st->cstack);
+									if (conditional_active(st->cstack))
+										st->state = CSTATE_START_COMMAND;
+								}
+								/* could detect "else" & "elif" after "else" */
+								st->command++;
+								break;
+
+							case IFSTATE_NONE:
+							case IFSTATE_TRUE:
+							case IFSTATE_ELSE_TRUE:
+							default:
+
+								/*
+								 * inconsistent if inactive, unreachable dead
+								 * code
+								 */
+								Assert(false);
+						}
+					}
+					else
+					{
+						/* skip and consider next */
+						st->command++;
+					}
+
+					if (st->state != CSTATE_SKIP_COMMAND)
+						/* out of quick skip command loop */
+						break;
+				}
+				break;
+
+				/*
+				 * Wait for the current SQL command to complete
+				 */
+			case CSTATE_WAIT_RESULT:
+				pg_log_debug("client %d receiving", st->id);
+
+				/*
+				 * Only check for new network data if we processed all data
+				 * fetched prior. Otherwise we end up doing a syscall for each
+				 * individual pipelined query, which has a measurable
+				 * performance impact.
+				 */
+				if (PQisBusy(st->con) && !PQconsumeInput(st->con))
+				{
+					/* there's something wrong */
+					commandFailed(st, "SQL", "perhaps the backend died while processing");
+					st->state = CSTATE_ABORTED;
+					break;
+				}
+				if (PQisBusy(st->con))
+					return;		/* don't have the whole result yet */
+
+				/* store or discard the query results */
+				if (readCommandResponse(st,
+										sql_script[st->use_file].commands[st->command]->meta,
+										sql_script[st->use_file].commands[st->command]->varprefix))
+				{
+					/*
+					 * outside of pipeline mode: stop reading results.
+					 * pipeline mode: continue reading results until an
+					 * end-of-pipeline response.
+					 */
+					if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
+						st->state = CSTATE_END_COMMAND;
+				}
+				else
+					st->state = CSTATE_ABORTED;
+				break;
+
+				/*
+				 * Wait until sleep is done. This state is entered after a
+				 * \sleep metacommand. The behavior is similar to
+				 * CSTATE_THROTTLE, but proceeds to CSTATE_START_COMMAND
+				 * instead of CSTATE_START_TX.
+				 */
+			case CSTATE_SLEEP:
+				pg_time_now_lazy(&now);
+				if (now < st->sleep_until)
+					return;		/* still sleeping, nothing to do here */
+				/* Else done sleeping. */
+				st->state = CSTATE_END_COMMAND;
+				break;
+
+				/*
+				 * End of command: record stats and proceed to next command.
+				 */
+			case CSTATE_END_COMMAND:
+
+				/*
+				 * command completed: accumulate per-command execution times
+				 * in thread-local data structure, if per-command latencies
+				 * are requested.
+				 */
+				if (report_per_command)
+				{
+					Command    *command;
+
+					pg_time_now_lazy(&now);
+
+					command = sql_script[st->use_file].commands[st->command];
+					/* XXX could use a mutex here, but we choose not to */
+					addToSimpleStats(&command->stats,
+									 PG_TIME_GET_DOUBLE(now - st->stmt_begin));
+				}
+
+				/* Go ahead with next command, to be executed or skipped */
+				st->command++;
+				st->state = conditional_active(st->cstack) ?
+					CSTATE_START_COMMAND : CSTATE_SKIP_COMMAND;
+				break;
+
+				/*
+				 * End of transaction (end of script, really).
+				 */
+			case CSTATE_END_TX:
+
+				/* transaction finished: calculate latency and do log */
+				processXactStats(thread, st, &now, false, agg);
+
+				/*
+				 * missing \endif... cannot happen if CheckConditional was
+				 * okay
+				 */
+				Assert(conditional_stack_empty(st->cstack));
+
+				if (is_connect)
+				{
+					pg_time_usec_t start = now;
+
+					pg_time_now_lazy(&start);
+					finishCon(st);
+					now = pg_time_now();
+					thread->conn_duration += now - start;
+				}
+
+				if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
+				{
+					/* script completed */
+					st->state = CSTATE_FINISHED;
+					break;
+				}
+
+				/* next transaction (script) */
+				st->state = CSTATE_CHOOSE_SCRIPT;
+
+				/*
+				 * Ensure that we always return on this point, so as to avoid
+				 * an infinite loop if the script only contains meta commands.
+				 */
+				return;
+
+				/*
+				 * Final states.  Close the connection if it's still open.
+				 */
+			case CSTATE_ABORTED:
+			case CSTATE_FINISHED:
+
+				/*
+				 * Don't measure the disconnection delays here even if in
+				 * CSTATE_FINISHED and -C/--connect option is specified.
+				 * Because in this case all the connections that this thread
+				 * established are closed at the end of transactions and the
+				 * disconnection delays should have already been measured at
+				 * that moment.
+				 *
+				 * In CSTATE_ABORTED state, the measurement is no longer
+				 * necessary because we cannot report complete results anyways
+				 * in this case.
+				 */
+				finishCon(st);
+				return;
+		}
+	}
+}
+
+/*
+ * Subroutine for advanceConnectionState -- initiate or execute the current
+ * meta command, and return the next state to set.
+ *
+ * *now is updated to the current time, unless the command is expected to
+ * take no time to execute.
+ */
+static ConnectionStateEnum
+executeMetaCommand(CState *st, pg_time_usec_t *now)
+{
+	Command    *command = sql_script[st->use_file].commands[st->command];
+	int			argc;
+	char	  **argv;
+
+	Assert(command != NULL && command->type == META_COMMAND);
+
+	argc = command->argc;
+	argv = command->argv;
+
+	if (unlikely(__pg_log_level <= PG_LOG_DEBUG))
+	{
+		PQExpBufferData buf;
+
+		initPQExpBuffer(&buf);
+
+		printfPQExpBuffer(&buf, "client %d executing \\%s", st->id, argv[0]);
+		for (int i = 1; i < argc; i++)
+			appendPQExpBuffer(&buf, " %s", argv[i]);
+
+		pg_log_debug("%s", buf.data);
+
+		termPQExpBuffer(&buf);
+	}
+
+	if (command->meta == META_SLEEP)
+	{
+		int			usec;
+
+		/*
+		 * A \sleep doesn't execute anything, we just get the delay from the
+		 * argument, and enter the CSTATE_SLEEP state.  (The per-command
+		 * latency will be recorded in CSTATE_SLEEP state, not here, after the
+		 * delay has elapsed.)
+		 */
+		if (!evaluateSleep(st, argc, argv, &usec))
+		{
+			commandFailed(st, "sleep", "execution of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+
+		pg_time_now_lazy(now);
+		st->sleep_until = (*now) + usec;
+		return CSTATE_SLEEP;
+	}
+	else if (command->meta == META_SET)
+	{
+		PgBenchExpr *expr = command->expr;
+		PgBenchValue result;
+
+		if (!evaluateExpr(st, expr, &result))
+		{
+			commandFailed(st, argv[0], "evaluation of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+
+		if (!putVariableValue(st, argv[0], argv[1], &result))
+		{
+			commandFailed(st, "set", "assignment of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+	}
+	else if (command->meta == META_IF)
+	{
+		/* backslash commands with an expression to evaluate */
+		PgBenchExpr *expr = command->expr;
+		PgBenchValue result;
+		bool		cond;
+
+		if (!evaluateExpr(st, expr, &result))
+		{
+			commandFailed(st, argv[0], "evaluation of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+
+		cond = valueTruth(&result);
+		conditional_stack_push(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
+	}
+	else if (command->meta == META_ELIF)
+	{
+		/* backslash commands with an expression to evaluate */
+		PgBenchExpr *expr = command->expr;
+		PgBenchValue result;
+		bool		cond;
+
+		if (conditional_stack_peek(st->cstack) == IFSTATE_TRUE)
+		{
+			/* elif after executed block, skip eval and wait for endif. */
+			conditional_stack_poke(st->cstack, IFSTATE_IGNORED);
+			return CSTATE_END_COMMAND;
+		}
+
+		if (!evaluateExpr(st, expr, &result))
+		{
+			commandFailed(st, argv[0], "evaluation of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+
+		cond = valueTruth(&result);
+		Assert(conditional_stack_peek(st->cstack) == IFSTATE_FALSE);
+		conditional_stack_poke(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
+	}
+	else if (command->meta == META_ELSE)
+	{
+		switch (conditional_stack_peek(st->cstack))
+		{
+			case IFSTATE_TRUE:
+				conditional_stack_poke(st->cstack, IFSTATE_ELSE_FALSE);
+				break;
+			case IFSTATE_FALSE: /* inconsistent if active */
+			case IFSTATE_IGNORED:	/* inconsistent if active */
+			case IFSTATE_NONE:	/* else without if */
+			case IFSTATE_ELSE_TRUE: /* else after else */
+			case IFSTATE_ELSE_FALSE:	/* else after else */
+			default:
+				/* dead code if conditional check is ok */
+				Assert(false);
+		}
+	}
+	else if (command->meta == META_ENDIF)
+	{
+		Assert(!conditional_stack_empty(st->cstack));
+		conditional_stack_pop(st->cstack);
+	}
+	else if (command->meta == META_SETSHELL)
+	{
+		if (!runShellCommand(st, argv[1], argv + 2, argc - 2))
+		{
+			commandFailed(st, "setshell", "execution of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+	}
+	else if (command->meta == META_SHELL)
+	{
+		if (!runShellCommand(st, NULL, argv + 1, argc - 1))
+		{
+			commandFailed(st, "shell", "execution of meta-command failed");
+			return CSTATE_ABORTED;
+		}
+	}
+	else if (command->meta == META_STARTPIPELINE)
+	{
+		/*
+		 * In pipeline mode, we use a workflow based on libpq pipeline
+		 * functions.
+		 */
+		if (querymode == QUERY_SIMPLE)
+		{
+			commandFailed(st, "startpipeline", "cannot use pipeline mode with the simple query protocol");
+			return CSTATE_ABORTED;
+		}
+
+		if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
+		{
+			commandFailed(st, "startpipeline", "already in pipeline mode");
+			return CSTATE_ABORTED;
+		}
+		if (PQenterPipelineMode(st->con) == 0)
+		{
+			commandFailed(st, "startpipeline", "failed to enter pipeline mode");
+			return CSTATE_ABORTED;
+		}
+	}
+	else if (command->meta == META_ENDPIPELINE)
+	{
+		if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
+		{
+			commandFailed(st, "endpipeline", "not in pipeline mode");
+			return CSTATE_ABORTED;
+		}
+		if (!PQpipelineSync(st->con))
+		{
+			commandFailed(st, "endpipeline", "failed to send a pipeline sync");
+			return CSTATE_ABORTED;
+		}
+		/* Now wait for the PGRES_PIPELINE_SYNC and exit pipeline mode there */
+		/* collect pending results before getting out of pipeline mode */
+		return CSTATE_WAIT_RESULT;
+	}
+
+	/*
+	 * executing the expression or shell command might have taken a
+	 * non-negligible amount of time, so reset 'now'
+	 */
+	*now = 0;
+
+	return CSTATE_END_COMMAND;
+}
+
+/*
+ * Print log entry after completing one transaction.
+ *
+ * We print Unix-epoch timestamps in the log, so that entries can be
+ * correlated against other logs.
+ *
+ * XXX We could obtain the time from the caller and just shift it here, to
+ * avoid the cost of an extra call to pg_time_now().
+ */
+static void
+doLog(TState *thread, CState *st,
+	  StatsData *agg, bool skipped, double latency, double lag)
+{
+	FILE	   *logfile = thread->logfile;
+	pg_time_usec_t now = pg_time_now() + epoch_shift;
+
+	Assert(use_log);
+
+	/*
+	 * Skip the log entry if sampling is enabled and this row doesn't belong
+	 * to the random sample.
+	 */
+	if (sample_rate != 0.0 &&
+		pg_erand48(thread->ts_sample_rs.xseed) > sample_rate)
+		return;
+
+	/* should we aggregate the results or not? */
+	if (agg_interval > 0)
+	{
+		pg_time_usec_t next;
+
+		/*
+		 * Loop until we reach the interval of the current moment, and print
+		 * any empty intervals in between (this may happen with very low tps,
+		 * e.g. --rate=0.1).
+		 */
+
+		while ((next = agg->start_time + agg_interval * INT64CONST(1000000)) <= now)
+		{
+			/* print aggregated report to logfile */
+			fprintf(logfile, INT64_FORMAT " " INT64_FORMAT " %.0f %.0f %.0f %.0f",
+					agg->start_time / 1000000,	/* seconds since Unix epoch */
+					agg->cnt,
+					agg->latency.sum,
+					agg->latency.sum2,
+					agg->latency.min,
+					agg->latency.max);
+			if (throttle_delay)
+			{
+				fprintf(logfile, " %.0f %.0f %.0f %.0f",
+						agg->lag.sum,
+						agg->lag.sum2,
+						agg->lag.min,
+						agg->lag.max);
+				if (latency_limit)
+					fprintf(logfile, " " INT64_FORMAT, agg->skipped);
+			}
+			fputc('\n', logfile);
+
+			/* reset data and move to next interval */
+			initStats(agg, next);
+		}
+
+		/* accumulate the current transaction */
+		accumStats(agg, skipped, latency, lag);
+	}
+	else
+	{
+		/* no, print raw transactions */
+		if (skipped)
+			fprintf(logfile, "%d " INT64_FORMAT " skipped %d " INT64_FORMAT " "
+					INT64_FORMAT,
+					st->id, st->cnt, st->use_file, now / 1000000, now % 1000000);
+		else
+			fprintf(logfile, "%d " INT64_FORMAT " %.0f %d " INT64_FORMAT " "
+					INT64_FORMAT,
+					st->id, st->cnt, latency, st->use_file,
+					now / 1000000, now % 1000000);
+		if (throttle_delay)
+			fprintf(logfile, " %.0f", lag);
+		fputc('\n', logfile);
+	}
+}
+
+/*
+ * Accumulate and report statistics at end of a transaction.
+ *
+ * (This is also called when a transaction is late and thus skipped.
+ * Note that even skipped transactions are counted in the "cnt" fields.)
+ */
+static void
+processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
+				 bool skipped, StatsData *agg)
+{
+	double		latency = 0.0,
+				lag = 0.0;
+	bool		thread_details = progress || throttle_delay || latency_limit,
+				detailed = thread_details || use_log || per_script_stats;
+
+	if (detailed && !skipped)
+	{
+		pg_time_now_lazy(now);
+
+		/* compute latency & lag */
+		latency = (*now) - st->txn_scheduled;
+		lag = st->txn_begin - st->txn_scheduled;
+	}
+
+	if (thread_details)
+	{
+		/* keep detailed thread stats */
+		accumStats(&thread->stats, skipped, latency, lag);
+
+		/* count transactions over the latency limit, if needed */
+		if (latency_limit && latency > latency_limit)
+			thread->latency_late++;
+	}
+	else
+	{
+		/* no detailed stats, just count */
+		thread->stats.cnt++;
+	}
+
+	/* client stat is just counting */
+	st->cnt++;
+
+	if (use_log)
+		doLog(thread, st, agg, skipped, latency, lag);
+
+	/* XXX could use a mutex here, but we choose not to */
+	if (per_script_stats)
+		accumStats(&sql_script[st->use_file].stats, skipped, latency, lag);
+}
+
+
+/* discard connections */
+static void
+disconnect_all(CState *state, int length)
+{
+	int			i;
+
+	for (i = 0; i < length; i++)
+		finishCon(&state[i]);
+}
+
+/*
+ * Remove old pgbench tables, if any exist
+ */
+static void
+initDropTables(PGconn *con)
+{
+	fprintf(stderr, "dropping old tables...\n");
+
+	/*
+	 * We drop all the tables in one command, so that whether there are
+	 * foreign key dependencies or not doesn't matter.
+	 */
+	executeStatement(con, "drop table if exists "
+					 "pgbench_accounts, "
+					 "pgbench_branches, "
+					 "pgbench_history, "
+					 "pgbench_tellers");
+}
+
+/*
+ * Create "pgbench_accounts" partitions if needed.
+ *
+ * This is the larger table of pgbench default tpc-b like schema
+ * with a known size, so we choose to partition it.
+ */
+static void
+createPartitions(PGconn *con)
+{
+	PQExpBufferData query;
+
+	/* we must have to create some partitions */
+	Assert(partitions > 0);
+
+	fprintf(stderr, "creating %d partitions...\n", partitions);
+
+	initPQExpBuffer(&query);
+
+	for (int p = 1; p <= partitions; p++)
+	{
+		if (partition_method == PART_RANGE)
+		{
+			int64		part_size = (naccounts * (int64) scale + partitions - 1) / partitions;
+
+			printfPQExpBuffer(&query,
+							  "create%s table pgbench_accounts_%d\n"
+							  "  partition of pgbench_accounts\n"
+							  "  for values from (",
+							  unlogged_tables ? " unlogged" : "", p);
+
+			/*
+			 * For RANGE, we use open-ended partitions at the beginning and
+			 * end to allow any valid value for the primary key.  Although the
+			 * actual minimum and maximum values can be derived from the
+			 * scale, it is more generic and the performance is better.
+			 */
+			if (p == 1)
+				appendPQExpBufferStr(&query, "minvalue");
+			else
+				appendPQExpBuffer(&query, INT64_FORMAT, (p - 1) * part_size + 1);
+
+			appendPQExpBufferStr(&query, ") to (");
+
+			if (p < partitions)
+				appendPQExpBuffer(&query, INT64_FORMAT, p * part_size + 1);
+			else
+				appendPQExpBufferStr(&query, "maxvalue");
+
+			appendPQExpBufferChar(&query, ')');
+		}
+		else if (partition_method == PART_HASH)
+			printfPQExpBuffer(&query,
+							  "create%s table pgbench_accounts_%d\n"
+							  "  partition of pgbench_accounts\n"
+							  "  for values with (modulus %d, remainder %d)",
+							  unlogged_tables ? " unlogged" : "", p,
+							  partitions, p - 1);
+		else					/* cannot get there */
+			Assert(0);
+
+		/*
+		 * Per ddlinfo in initCreateTables, fillfactor is needed on table
+		 * pgbench_accounts.
+		 */
+		appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);
+
+		executeStatement(con, query.data);
+	}
+
+	termPQExpBuffer(&query);
+}
+
+/*
+ * Create pgbench's standard tables
+ */
+static void
+initCreateTables(PGconn *con)
+{
+	/*
+	 * Note: TPC-B requires at least 100 bytes per row, and the "filler"
+	 * fields in these table declarations were intended to comply with that.
+	 * The pgbench_accounts table complies with that because the "filler"
+	 * column is set to blank-padded empty string. But for all other tables
+	 * the columns default to NULL and so don't actually take any space.  We
+	 * could fix that by giving them non-null default values.  However, that
+	 * would completely break comparability of pgbench results with prior
+	 * versions. Since pgbench has never pretended to be fully TPC-B compliant
+	 * anyway, we stick with the historical behavior.
+	 */
+	struct ddlinfo
+	{
+		const char *table;		/* table name */
+		const char *smcols;		/* column decls if accountIDs are 32 bits */
+		const char *bigcols;	/* column decls if accountIDs are 64 bits */
+		int			declare_fillfactor;
+	};
+	static const struct ddlinfo DDLs[] = {
+		{
+			"pgbench_history",
+			"tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
+			"tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)",
+			0
+		},
+		{
+			"pgbench_tellers",
+			"tid int not null,bid int,tbalance int,filler char(84)",
+			"tid int not null,bid int,tbalance int,filler char(84)",
+			1
+		},
+		{
+			"pgbench_accounts",
+			"aid    int not null,bid int,abalance int,filler char(84)",
+			"aid bigint not null,bid int,abalance int,filler char(84)",
+			1
+		},
+		{
+			"pgbench_branches",
+			"bid int not null,bbalance int,filler char(88)",
+			"bid int not null,bbalance int,filler char(88)",
+			1
+		}
+	};
+	int			i;
+	PQExpBufferData query;
+
+	fprintf(stderr, "creating tables...\n");
+
+	initPQExpBuffer(&query);
+
+	for (i = 0; i < lengthof(DDLs); i++)
+	{
+		const struct ddlinfo *ddl = &DDLs[i];
+
+		/* Construct new create table statement. */
+		printfPQExpBuffer(&query, "create%s table %s(%s)",
+						  unlogged_tables ? " unlogged" : "",
+						  ddl->table,
+						  (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols);
+
+		/* Partition pgbench_accounts table */
+		if (partition_method != PART_NONE && strcmp(ddl->table, "pgbench_accounts") == 0)
+			appendPQExpBuffer(&query,
+							  " partition by %s (aid)", PARTITION_METHOD[partition_method]);
+		else if (ddl->declare_fillfactor)
+		{
+			/* fillfactor is only expected on actual tables */
+			appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);
+		}
+
+		if (tablespace != NULL)
+		{
+			char	   *escape_tablespace;
+
+			escape_tablespace = PQescapeIdentifier(con, tablespace, strlen(tablespace));
+			appendPQExpBuffer(&query, " tablespace %s", escape_tablespace);
+			PQfreemem(escape_tablespace);
+		}
+
+		executeStatement(con, query.data);
+	}
+
+	termPQExpBuffer(&query);
+
+	if (partition_method != PART_NONE)
+		createPartitions(con);
+}
+
+/*
+ * Truncate away any old data, in one command in case there are foreign keys
+ */
+static void
+initTruncateTables(PGconn *con)
+{
+	executeStatement(con, "truncate table "
+					 "pgbench_accounts, "
+					 "pgbench_branches, "
+					 "pgbench_history, "
+					 "pgbench_tellers");
+}
+
+/*
+ * Fill the standard tables with some data generated and sent from the client
+ */
+static void
+initGenerateDataClientSide(PGconn *con)
+{
+	PQExpBufferData sql;
+	PGresult   *res;
+	int			i;
+	int64		k;
+
+	/* used to track elapsed time and estimate of the remaining time */
+	pg_time_usec_t start;
+	int			log_interval = 1;
+
+	/* Stay on the same line if reporting to a terminal */
+	char		eol = isatty(fileno(stderr)) ? '\r' : '\n';
+
+	fprintf(stderr, "generating data (client-side)...\n");
+
+	/*
+	 * we do all of this in one transaction to enable the backend's
+	 * data-loading optimizations
+	 */
+	executeStatement(con, "begin");
+
+	/* truncate away any old data */
+	initTruncateTables(con);
+
+	initPQExpBuffer(&sql);
+
+	/*
+	 * fill branches, tellers, accounts in that order in case foreign keys
+	 * already exist
+	 */
+	for (i = 0; i < nbranches * scale; i++)
+	{
+		/* "filler" column defaults to NULL */
+		printfPQExpBuffer(&sql,
+						  "insert into pgbench_branches(bid,bbalance) values(%d,0)",
+						  i + 1);
+		executeStatement(con, sql.data);
+	}
+
+	for (i = 0; i < ntellers * scale; i++)
+	{
+		/* "filler" column defaults to NULL */
+		printfPQExpBuffer(&sql,
+						  "insert into pgbench_tellers(tid,bid,tbalance) values (%d,%d,0)",
+						  i + 1, i / ntellers + 1);
+		executeStatement(con, sql.data);
+	}
+
+	/*
+	 * accounts is big enough to be worth using COPY and tracking runtime
+	 */
+	res = PQexec(con, "copy pgbench_accounts from stdin");
+	if (PQresultStatus(res) != PGRES_COPY_IN)
+	{
+		pg_log_fatal("unexpected copy in result: %s", PQerrorMessage(con));
+		exit(1);
+	}
+	PQclear(res);
+
+	start = pg_time_now();
+
+	for (k = 0; k < (int64) naccounts * scale; k++)
+	{
+		int64		j = k + 1;
+
+		/* "filler" column defaults to blank padded empty string */
+		printfPQExpBuffer(&sql,
+						  INT64_FORMAT "\t" INT64_FORMAT "\t%d\t\n",
+						  j, k / naccounts + 1, 0);
+		if (PQputline(con, sql.data))
+		{
+			pg_log_fatal("PQputline failed");
+			exit(1);
+		}
+
+		if (CancelRequested)
+			break;
+
+		/*
+		 * If we want to stick with the original logging, print a message each
+		 * 100k inserted rows.
+		 */
+		if ((!use_quiet) && (j % 100000 == 0))
+		{
+			double		elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
+			double		remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
+
+			fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)%c",
+					j, (int64) naccounts * scale,
+					(int) (((int64) j * 100) / (naccounts * (int64) scale)),
+					elapsed_sec, remaining_sec, eol);
+		}
+		/* let's not call the timing for each row, but only each 100 rows */
+		else if (use_quiet && (j % 100 == 0))
+		{
+			double		elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
+			double		remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;
+
+			/* have we reached the next interval (or end)? */
+			if ((j == scale * naccounts) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
+			{
+				fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)%c",
+						j, (int64) naccounts * scale,
+						(int) (((int64) j * 100) / (naccounts * (int64) scale)), elapsed_sec, remaining_sec, eol);
+
+				/* skip to the next interval */
+				log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
+			}
+		}
+	}
+
+	if (eol != '\n')
+		fputc('\n', stderr);	/* Need to move to next line */
+
+	if (PQputline(con, "\\.\n"))
+	{
+		pg_log_fatal("very last PQputline failed");
+		exit(1);
+	}
+	if (PQendcopy(con))
+	{
+		pg_log_fatal("PQendcopy failed");
+		exit(1);
+	}
+
+	termPQExpBuffer(&sql);
+
+	executeStatement(con, "commit");
+}
+
+/*
+ * Fill the standard tables with some data generated on the server
+ *
+ * As already the case with the client-side data generation, the filler
+ * column defaults to NULL in pgbench_branches and pgbench_tellers,
+ * and is a blank-padded string in pgbench_accounts.
+ */
+static void
+initGenerateDataServerSide(PGconn *con)
+{
+	PQExpBufferData sql;
+
+	fprintf(stderr, "generating data (server-side)...\n");
+
+	/*
+	 * we do all of this in one transaction to enable the backend's
+	 * data-loading optimizations
+	 */
+	executeStatement(con, "begin");
+
+	/* truncate away any old data */
+	initTruncateTables(con);
+
+	initPQExpBuffer(&sql);
+
+	printfPQExpBuffer(&sql,
+					  "insert into pgbench_branches(bid,bbalance) "
+					  "select bid, 0 "
+					  "from generate_series(1, %d) as bid", nbranches * scale);
+	executeStatement(con, sql.data);
+
+	printfPQExpBuffer(&sql,
+					  "insert into pgbench_tellers(tid,bid,tbalance) "
+					  "select tid, (tid - 1) / %d + 1, 0 "
+					  "from generate_series(1, %d) as tid", ntellers, ntellers * scale);
+	executeStatement(con, sql.data);
+
+	printfPQExpBuffer(&sql,
+					  "insert into pgbench_accounts(aid,bid,abalance,filler) "
+					  "select aid, (aid - 1) / %d + 1, 0, '' "
+					  "from generate_series(1, " INT64_FORMAT ") as aid",
+					  naccounts, (int64) naccounts * scale);
+	executeStatement(con, sql.data);
+
+	termPQExpBuffer(&sql);
+
+	executeStatement(con, "commit");
+}
+
+/*
+ * Invoke vacuum on the standard tables
+ */
+static void
+initVacuum(PGconn *con)
+{
+	fprintf(stderr, "vacuuming...\n");
+	executeStatement(con, "vacuum analyze pgbench_branches");
+	executeStatement(con, "vacuum analyze pgbench_tellers");
+	executeStatement(con, "vacuum analyze pgbench_accounts");
+	executeStatement(con, "vacuum analyze pgbench_history");
+}
+
+/*
+ * Create primary keys on the standard tables
+ */
+static void
+initCreatePKeys(PGconn *con)
+{
+	static const char *const DDLINDEXes[] = {
+		"alter table pgbench_branches add primary key (bid)",
+		"alter table pgbench_tellers add primary key (tid)",
+		"alter table pgbench_accounts add primary key (aid)"
+	};
+	int			i;
+	PQExpBufferData query;
+
+	fprintf(stderr, "creating primary keys...\n");
+	initPQExpBuffer(&query);
+
+	for (i = 0; i < lengthof(DDLINDEXes); i++)
+	{
+		resetPQExpBuffer(&query);
+		appendPQExpBufferStr(&query, DDLINDEXes[i]);
+
+		if (index_tablespace != NULL)
+		{
+			char	   *escape_tablespace;
+
+			escape_tablespace = PQescapeIdentifier(con, index_tablespace,
+												   strlen(index_tablespace));
+			appendPQExpBuffer(&query, " using index tablespace %s", escape_tablespace);
+			PQfreemem(escape_tablespace);
+		}
+
+		executeStatement(con, query.data);
+	}
+
+	termPQExpBuffer(&query);
+}
+
+/*
+ * Create foreign key constraints between the standard tables
+ */
+static void
+initCreateFKeys(PGconn *con)
+{
+	static const char *const DDLKEYs[] = {
+		"alter table pgbench_tellers add constraint pgbench_tellers_bid_fkey foreign key (bid) references pgbench_branches",
+		"alter table pgbench_accounts add constraint pgbench_accounts_bid_fkey foreign key (bid) references pgbench_branches",
+		"alter table pgbench_history add constraint pgbench_history_bid_fkey foreign key (bid) references pgbench_branches",
+		"alter table pgbench_history add constraint pgbench_history_tid_fkey foreign key (tid) references pgbench_tellers",
+		"alter table pgbench_history add constraint pgbench_history_aid_fkey foreign key (aid) references pgbench_accounts"
+	};
+	int			i;
+
+	fprintf(stderr, "creating foreign keys...\n");
+	for (i = 0; i < lengthof(DDLKEYs); i++)
+	{
+		executeStatement(con, DDLKEYs[i]);
+	}
+}
+
+/*
+ * Validate an initialization-steps string
+ *
+ * (We could just leave it to runInitSteps() to fail if there are wrong
+ * characters, but since initialization can take awhile, it seems friendlier
+ * to check during option parsing.)
+ */
+static void
+checkInitSteps(const char *initialize_steps)
+{
+	if (initialize_steps[0] == '\0')
+	{
+		pg_log_fatal("no initialization steps specified");
+		exit(1);
+	}
+
+	for (const char *step = initialize_steps; *step != '\0'; step++)
+	{
+		if (strchr(ALL_INIT_STEPS " ", *step) == NULL)
+		{
+			pg_log_fatal("unrecognized initialization step \"%c\"", *step);
+			pg_log_info("Allowed step characters are: \"" ALL_INIT_STEPS "\".");
+			exit(1);
+		}
+	}
+}
+
+/*
+ * Invoke each initialization step in the given string
+ */
+static void
+runInitSteps(const char *initialize_steps)
+{
+	PQExpBufferData stats;
+	PGconn	   *con;
+	const char *step;
+	double		run_time = 0.0;
+	bool		first = true;
+
+	initPQExpBuffer(&stats);
+
+	if ((con = doConnect()) == NULL)
+		exit(1);
+
+	setup_cancel_handler(NULL);
+	SetCancelConn(con);
+
+	for (step = initialize_steps; *step != '\0'; step++)
+	{
+		char	   *op = NULL;
+		pg_time_usec_t start = pg_time_now();
+
+		switch (*step)
+		{
+			case 'd':
+				op = "drop tables";
+				initDropTables(con);
+				break;
+			case 't':
+				op = "create tables";
+				initCreateTables(con);
+				break;
+			case 'g':
+				op = "client-side generate";
+				initGenerateDataClientSide(con);
+				break;
+			case 'G':
+				op = "server-side generate";
+				initGenerateDataServerSide(con);
+				break;
+			case 'v':
+				op = "vacuum";
+				initVacuum(con);
+				break;
+			case 'p':
+				op = "primary keys";
+				initCreatePKeys(con);
+				break;
+			case 'f':
+				op = "foreign keys";
+				initCreateFKeys(con);
+				break;
+			case ' ':
+				break;			/* ignore */
+			default:
+				pg_log_fatal("unrecognized initialization step \"%c\"", *step);
+				PQfinish(con);
+				exit(1);
+		}
+
+		if (op != NULL)
+		{
+			double		elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
+
+			if (!first)
+				appendPQExpBufferStr(&stats, ", ");
+			else
+				first = false;
+
+			appendPQExpBuffer(&stats, "%s %.2f s", op, elapsed_sec);
+
+			run_time += elapsed_sec;
+		}
+	}
+
+	fprintf(stderr, "done in %.2f s (%s).\n", run_time, stats.data);
+	ResetCancelConn();
+	PQfinish(con);
+	termPQExpBuffer(&stats);
+}
+
+/*
+ * Extract pgbench table information into global variables scale,
+ * partition_method and partitions.
+ */
+static void
+GetTableInfo(PGconn *con, bool scale_given)
+{
+	PGresult   *res;
+
+	/*
+	 * get the scaling factor that should be same as count(*) from
+	 * pgbench_branches if this is not a custom query
+	 */
+	res = PQexec(con, "select count(*) from pgbench_branches");
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
+	{
+		char	   *sqlState = PQresultErrorField(res, PG_DIAG_SQLSTATE);
+
+		pg_log_fatal("could not count number of branches: %s", PQerrorMessage(con));
+
+		if (sqlState && strcmp(sqlState, ERRCODE_UNDEFINED_TABLE) == 0)
+			pg_log_info("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\"",
+						PQdb(con));
+
+		exit(1);
+	}
+	scale = atoi(PQgetvalue(res, 0, 0));
+	if (scale < 0)
+	{
+		pg_log_fatal("invalid count(*) from pgbench_branches: \"%s\"",
+					 PQgetvalue(res, 0, 0));
+		exit(1);
+	}
+	PQclear(res);
+
+	/* warn if we override user-given -s switch */
+	if (scale_given)
+		pg_log_warning("scale option ignored, using count from pgbench_branches table (%d)",
+					   scale);
+
+	/*
+	 * Get the partition information for the first "pgbench_accounts" table
+	 * found in search_path.
+	 *
+	 * The result is empty if no "pgbench_accounts" is found.
+	 *
+	 * Otherwise, it always returns one row even if the table is not
+	 * partitioned (in which case the partition strategy is NULL).
+	 *
+	 * The number of partitions can be 0 even for partitioned tables, if no
+	 * partition is attached.
+	 *
+	 * We assume no partitioning on any failure, so as to avoid failing on an
+	 * old version without "pg_partitioned_table".
+	 */
+	res = PQexec(con,
+				 "select o.n, p.partstrat, pg_catalog.count(i.inhparent) "
+				 "from pg_catalog.pg_class as c "
+				 "join pg_catalog.pg_namespace as n on (n.oid = c.relnamespace) "
+				 "cross join lateral (select pg_catalog.array_position(pg_catalog.current_schemas(true), n.nspname)) as o(n) "
+				 "left join pg_catalog.pg_partitioned_table as p on (p.partrelid = c.oid) "
+				 "left join pg_catalog.pg_inherits as i on (c.oid = i.inhparent) "
+				 "where c.relname = 'pgbench_accounts' and o.n is not null "
+				 "group by 1, 2 "
+				 "order by 1 asc "
+				 "limit 1");
+
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
+	{
+		/* probably an older version, coldly assume no partitioning */
+		partition_method = PART_NONE;
+		partitions = 0;
+	}
+	else if (PQntuples(res) == 0)
+	{
+		/*
+		 * This case is unlikely as pgbench already found "pgbench_branches"
+		 * above to compute the scale.
+		 */
+		pg_log_fatal("no pgbench_accounts table found in search_path");
+		pg_log_info("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\".", PQdb(con));
+		exit(1);
+	}
+	else						/* PQntupes(res) == 1 */
+	{
+		/* normal case, extract partition information */
+		if (PQgetisnull(res, 0, 1))
+			partition_method = PART_NONE;
+		else
+		{
+			char	   *ps = PQgetvalue(res, 0, 1);
+
+			/* column must be there */
+			Assert(ps != NULL);
+
+			if (strcmp(ps, "r") == 0)
+				partition_method = PART_RANGE;
+			else if (strcmp(ps, "h") == 0)
+				partition_method = PART_HASH;
+			else
+			{
+				/* possibly a newer version with new partition method */
+				pg_log_fatal("unexpected partition method: \"%s\"", ps);
+				exit(1);
+			}
+		}
+
+		partitions = atoi(PQgetvalue(res, 0, 2));
+	}
+
+	PQclear(res);
+}
+
+/*
+ * Replace :param with $n throughout the command's SQL text, which
+ * is a modifiable string in cmd->lines.
+ */
+static bool
+parseQuery(Command *cmd)
+{
+	char	   *sql,
+			   *p;
+
+	cmd->argc = 1;
+
+	p = sql = pg_strdup(cmd->lines.data);
+	while ((p = strchr(p, ':')) != NULL)
+	{
+		char		var[13];
+		char	   *name;
+		int			eaten;
+
+		name = parseVariable(p, &eaten);
+		if (name == NULL)
+		{
+			while (*p == ':')
+			{
+				p++;
+			}
+			continue;
+		}
+
+		/*
+		 * cmd->argv[0] is the SQL statement itself, so the max number of
+		 * arguments is one less than MAX_ARGS
+		 */
+		if (cmd->argc >= MAX_ARGS)
+		{
+			pg_log_error("statement has too many arguments (maximum is %d): %s",
+						 MAX_ARGS - 1, cmd->lines.data);
+			pg_free(name);
+			return false;
+		}
+
+		sprintf(var, "$%d", cmd->argc);
+		p = replaceVariable(&sql, p, eaten, var);
+
+		cmd->argv[cmd->argc] = name;
+		cmd->argc++;
+	}
+
+	Assert(cmd->argv[0] == NULL);
+	cmd->argv[0] = sql;
+	return true;
+}
+
+/*
+ * syntax error while parsing a script (in practice, while parsing a
+ * backslash command, because we don't detect syntax errors in SQL)
+ *
+ * source: source of script (filename or builtin-script ID)
+ * lineno: line number within script (count from 1)
+ * line: whole line of backslash command, if available
+ * command: backslash command name, if available
+ * msg: the actual error message
+ * more: optional extra message
+ * column: zero-based column number, or -1 if unknown
+ */
+void
+syntax_error(const char *source, int lineno,
+			 const char *line, const char *command,
+			 const char *msg, const char *more, int column)
+{
+	PQExpBufferData buf;
+
+	initPQExpBuffer(&buf);
+
+	printfPQExpBuffer(&buf, "%s:%d: %s", source, lineno, msg);
+	if (more != NULL)
+		appendPQExpBuffer(&buf, " (%s)", more);
+	if (column >= 0 && line == NULL)
+		appendPQExpBuffer(&buf, " at column %d", column + 1);
+	if (command != NULL)
+		appendPQExpBuffer(&buf, " in command \"%s\"", command);
+
+	pg_log_fatal("%s", buf.data);
+
+	termPQExpBuffer(&buf);
+
+	if (line != NULL)
+	{
+		fprintf(stderr, "%s\n", line);
+		if (column >= 0)
+			fprintf(stderr, "%*c error found here\n", column + 1, '^');
+	}
+
+	exit(1);
+}
+
+/*
+ * Return a pointer to the start of the SQL command, after skipping over
+ * whitespace and "--" comments.
+ * If the end of the string is reached, return NULL.
+ */
+static char *
+skip_sql_comments(char *sql_command)
+{
+	char	   *p = sql_command;
+
+	/* Skip any leading whitespace, as well as "--" style comments */
+	for (;;)
+	{
+		if (isspace((unsigned char) *p))
+			p++;
+		else if (strncmp(p, "--", 2) == 0)
+		{
+			p = strchr(p, '\n');
+			if (p == NULL)
+				return NULL;
+			p++;
+		}
+		else
+			break;
+	}
+
+	/* NULL if there's nothing but whitespace and comments */
+	if (*p == '\0')
+		return NULL;
+
+	return p;
+}
+
+/*
+ * Parse a SQL command; return a Command struct, or NULL if it's a comment
+ *
+ * On entry, psqlscan.l has collected the command into "buf", so we don't
+ * really need to do much here except check for comments and set up a Command
+ * struct.
+ */
+static Command *
+create_sql_command(PQExpBuffer buf, const char *source)
+{
+	Command    *my_command;
+	char	   *p = skip_sql_comments(buf->data);
+
+	if (p == NULL)
+		return NULL;
+
+	/* Allocate and initialize Command structure */
+	my_command = (Command *) pg_malloc(sizeof(Command));
+	initPQExpBuffer(&my_command->lines);
+	appendPQExpBufferStr(&my_command->lines, p);
+	my_command->first_line = NULL;	/* this is set later */
+	my_command->type = SQL_COMMAND;
+	my_command->meta = META_NONE;
+	my_command->argc = 0;
+	memset(my_command->argv, 0, sizeof(my_command->argv));
+	my_command->varprefix = NULL;	/* allocated later, if needed */
+	my_command->expr = NULL;
+	initSimpleStats(&my_command->stats);
+
+	return my_command;
+}
+
+/* Free a Command structure and associated data */
+static void
+free_command(Command *command)
+{
+	termPQExpBuffer(&command->lines);
+	if (command->first_line)
+		pg_free(command->first_line);
+	for (int i = 0; i < command->argc; i++)
+		pg_free(command->argv[i]);
+	if (command->varprefix)
+		pg_free(command->varprefix);
+
+	/*
+	 * It should also free expr recursively, but this is currently not needed
+	 * as only gset commands (which do not have an expression) are freed.
+	 */
+	pg_free(command);
+}
+
+/*
+ * Once an SQL command is fully parsed, possibly by accumulating several
+ * parts, complete other fields of the Command structure.
+ */
+static void
+postprocess_sql_command(Command *my_command)
+{
+	char		buffer[128];
+
+	Assert(my_command->type == SQL_COMMAND);
+
+	/* Save the first line for error display. */
+	strlcpy(buffer, my_command->lines.data, sizeof(buffer));
+	buffer[strcspn(buffer, "\n\r")] = '\0';
+	my_command->first_line = pg_strdup(buffer);
+
+	/* parse query if necessary */
+	switch (querymode)
+	{
+		case QUERY_SIMPLE:
+			my_command->argv[0] = my_command->lines.data;
+			my_command->argc++;
+			break;
+		case QUERY_EXTENDED:
+		case QUERY_PREPARED:
+			if (!parseQuery(my_command))
+				exit(1);
+			break;
+		default:
+			exit(1);
+	}
+}
+
+/*
+ * Parse a backslash command; return a Command struct, or NULL if comment
+ *
+ * At call, we have scanned only the initial backslash.
+ */
+static Command *
+process_backslash_command(PsqlScanState sstate, const char *source)
+{
+	Command    *my_command;
+	PQExpBufferData word_buf;
+	int			word_offset;
+	int			offsets[MAX_ARGS];	/* offsets of argument words */
+	int			start_offset;
+	int			lineno;
+	int			j;
+
+	initPQExpBuffer(&word_buf);
+
+	/* Remember location of the backslash */
+	start_offset = expr_scanner_offset(sstate) - 1;
+	lineno = expr_scanner_get_lineno(sstate, start_offset);
+
+	/* Collect first word of command */
+	if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
+	{
+		termPQExpBuffer(&word_buf);
+		return NULL;
+	}
+
+	/* Allocate and initialize Command structure */
+	my_command = (Command *) pg_malloc0(sizeof(Command));
+	my_command->type = META_COMMAND;
+	my_command->argc = 0;
+	initSimpleStats(&my_command->stats);
+
+	/* Save first word (command name) */
+	j = 0;
+	offsets[j] = word_offset;
+	my_command->argv[j++] = pg_strdup(word_buf.data);
+	my_command->argc++;
+
+	/* ... and convert it to enum form */
+	my_command->meta = getMetaCommand(my_command->argv[0]);
+
+	if (my_command->meta == META_SET ||
+		my_command->meta == META_IF ||
+		my_command->meta == META_ELIF)
+	{
+		yyscan_t	yyscanner;
+
+		/* For \set, collect var name */
+		if (my_command->meta == META_SET)
+		{
+			if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
+				syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+							 "missing argument", NULL, -1);
+
+			offsets[j] = word_offset;
+			my_command->argv[j++] = pg_strdup(word_buf.data);
+			my_command->argc++;
+		}
+
+		/* then for all parse the expression */
+		yyscanner = expr_scanner_init(sstate, source, lineno, start_offset,
+									  my_command->argv[0]);
+
+		if (expr_yyparse(yyscanner) != 0)
+		{
+			/* dead code: exit done from syntax_error called by yyerror */
+			exit(1);
+		}
+
+		my_command->expr = expr_parse_result;
+
+		/* Save line, trimming any trailing newline */
+		my_command->first_line =
+			expr_scanner_get_substring(sstate,
+									   start_offset,
+									   expr_scanner_offset(sstate),
+									   true);
+
+		expr_scanner_finish(yyscanner);
+
+		termPQExpBuffer(&word_buf);
+
+		return my_command;
+	}
+
+	/* For all other commands, collect remaining words. */
+	while (expr_lex_one_word(sstate, &word_buf, &word_offset))
+	{
+		/*
+		 * my_command->argv[0] is the command itself, so the max number of
+		 * arguments is one less than MAX_ARGS
+		 */
+		if (j >= MAX_ARGS)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "too many arguments", NULL, -1);
+
+		offsets[j] = word_offset;
+		my_command->argv[j++] = pg_strdup(word_buf.data);
+		my_command->argc++;
+	}
+
+	/* Save line, trimming any trailing newline */
+	my_command->first_line =
+		expr_scanner_get_substring(sstate,
+								   start_offset,
+								   expr_scanner_offset(sstate),
+								   true);
+
+	if (my_command->meta == META_SLEEP)
+	{
+		if (my_command->argc < 2)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "missing argument", NULL, -1);
+
+		if (my_command->argc > 3)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "too many arguments", NULL,
+						 offsets[3] - start_offset);
+
+		/*
+		 * Split argument into number and unit to allow "sleep 1ms" etc. We
+		 * don't have to terminate the number argument with null because it
+		 * will be parsed with atoi, which ignores trailing non-digit
+		 * characters.
+		 */
+		if (my_command->argv[1][0] != ':')
+		{
+			char	   *c = my_command->argv[1];
+			bool		have_digit = false;
+
+			/* Skip sign */
+			if (*c == '+' || *c == '-')
+				c++;
+
+			/* Require at least one digit */
+			if (*c && isdigit((unsigned char) *c))
+				have_digit = true;
+
+			/* Eat all digits */
+			while (*c && isdigit((unsigned char) *c))
+				c++;
+
+			if (*c)
+			{
+				if (my_command->argc == 2 && have_digit)
+				{
+					my_command->argv[2] = c;
+					offsets[2] = offsets[1] + (c - my_command->argv[1]);
+					my_command->argc = 3;
+				}
+				else
+				{
+					/*
+					 * Raise an error if argument starts with non-digit
+					 * character (after sign).
+					 */
+					syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+								 "invalid sleep time, must be an integer",
+								 my_command->argv[1], offsets[1] - start_offset);
+				}
+			}
+		}
+
+		if (my_command->argc == 3)
+		{
+			if (pg_strcasecmp(my_command->argv[2], "us") != 0 &&
+				pg_strcasecmp(my_command->argv[2], "ms") != 0 &&
+				pg_strcasecmp(my_command->argv[2], "s") != 0)
+				syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+							 "unrecognized time unit, must be us, ms or s",
+							 my_command->argv[2], offsets[2] - start_offset);
+		}
+	}
+	else if (my_command->meta == META_SETSHELL)
+	{
+		if (my_command->argc < 3)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "missing argument", NULL, -1);
+	}
+	else if (my_command->meta == META_SHELL)
+	{
+		if (my_command->argc < 2)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "missing command", NULL, -1);
+	}
+	else if (my_command->meta == META_ELSE || my_command->meta == META_ENDIF ||
+			 my_command->meta == META_STARTPIPELINE ||
+			 my_command->meta == META_ENDPIPELINE)
+	{
+		if (my_command->argc != 1)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "unexpected argument", NULL, -1);
+	}
+	else if (my_command->meta == META_GSET || my_command->meta == META_ASET)
+	{
+		if (my_command->argc > 2)
+			syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+						 "too many arguments", NULL, -1);
+	}
+	else
+	{
+		/* my_command->meta == META_NONE */
+		syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
+					 "invalid command", NULL, -1);
+	}
+
+	termPQExpBuffer(&word_buf);
+
+	return my_command;
+}
+
+static void
+ConditionError(const char *desc, int cmdn, const char *msg)
+{
+	pg_log_fatal("condition error in script \"%s\" command %d: %s",
+				 desc, cmdn, msg);
+	exit(1);
+}
+
+/*
+ * Partial evaluation of conditionals before recording and running the script.
+ */
+static void
+CheckConditional(ParsedScript ps)
+{
+	/* statically check conditional structure */
+	ConditionalStack cs = conditional_stack_create();
+	int			i;
+
+	for (i = 0; ps.commands[i] != NULL; i++)
+	{
+		Command    *cmd = ps.commands[i];
+
+		if (cmd->type == META_COMMAND)
+		{
+			switch (cmd->meta)
+			{
+				case META_IF:
+					conditional_stack_push(cs, IFSTATE_FALSE);
+					break;
+				case META_ELIF:
+					if (conditional_stack_empty(cs))
+						ConditionError(ps.desc, i + 1, "\\elif without matching \\if");
+					if (conditional_stack_peek(cs) == IFSTATE_ELSE_FALSE)
+						ConditionError(ps.desc, i + 1, "\\elif after \\else");
+					break;
+				case META_ELSE:
+					if (conditional_stack_empty(cs))
+						ConditionError(ps.desc, i + 1, "\\else without matching \\if");
+					if (conditional_stack_peek(cs) == IFSTATE_ELSE_FALSE)
+						ConditionError(ps.desc, i + 1, "\\else after \\else");
+					conditional_stack_poke(cs, IFSTATE_ELSE_FALSE);
+					break;
+				case META_ENDIF:
+					if (!conditional_stack_pop(cs))
+						ConditionError(ps.desc, i + 1, "\\endif without matching \\if");
+					break;
+				default:
+					/* ignore anything else... */
+					break;
+			}
+		}
+	}
+	if (!conditional_stack_empty(cs))
+		ConditionError(ps.desc, i + 1, "\\if without matching \\endif");
+	conditional_stack_destroy(cs);
+}
+
+/*
+ * Parse a script (either the contents of a file, or a built-in script)
+ * and add it to the list of scripts.
+ */
+static void
+ParseScript(const char *script, const char *desc, int weight)
+{
+	ParsedScript ps;
+	PsqlScanState sstate;
+	PQExpBufferData line_buf;
+	int			alloc_num;
+	int			index;
+	int			lineno;
+	int			start_offset;
+
+#define COMMANDS_ALLOC_NUM 128
+	alloc_num = COMMANDS_ALLOC_NUM;
+
+	/* Initialize all fields of ps */
+	ps.desc = desc;
+	ps.weight = weight;
+	ps.commands = (Command **) pg_malloc(sizeof(Command *) * alloc_num);
+	initStats(&ps.stats, 0);
+
+	/* Prepare to parse script */
+	sstate = psql_scan_create(&pgbench_callbacks);
+
+	/*
+	 * Ideally, we'd scan scripts using the encoding and stdstrings settings
+	 * we get from a DB connection.  However, without major rearrangement of
+	 * pgbench's argument parsing, we can't have a DB connection at the time
+	 * we parse scripts.  Using SQL_ASCII (encoding 0) should work well enough
+	 * with any backend-safe encoding, though conceivably we could be fooled
+	 * if a script file uses a client-only encoding.  We also assume that
+	 * stdstrings should be true, which is a bit riskier.
+	 */
+	psql_scan_setup(sstate, script, strlen(script), 0, true);
+	start_offset = expr_scanner_offset(sstate) - 1;
+
+	initPQExpBuffer(&line_buf);
+
+	index = 0;
+
+	for (;;)
+	{
+		PsqlScanResult sr;
+		promptStatus_t prompt;
+		Command    *command = NULL;
+
+		resetPQExpBuffer(&line_buf);
+		lineno = expr_scanner_get_lineno(sstate, start_offset);
+
+		sr = psql_scan(sstate, &line_buf, &prompt);
+
+		/* If we collected a new SQL command, process that */
+		command = create_sql_command(&line_buf, desc);
+
+		/* store new command */
+		if (command)
+			ps.commands[index++] = command;
+
+		/* If we reached a backslash, process that */
+		if (sr == PSCAN_BACKSLASH)
+		{
+			command = process_backslash_command(sstate, desc);
+
+			if (command)
+			{
+				/*
+				 * If this is gset or aset, merge into the preceding command.
+				 * (We don't use a command slot in this case).
+				 */
+				if (command->meta == META_GSET || command->meta == META_ASET)
+				{
+					Command    *cmd;
+
+					if (index == 0)
+						syntax_error(desc, lineno, NULL, NULL,
+									 "\\gset must follow an SQL command",
+									 NULL, -1);
+
+					cmd = ps.commands[index - 1];
+
+					if (cmd->type != SQL_COMMAND ||
+						cmd->varprefix != NULL)
+						syntax_error(desc, lineno, NULL, NULL,
+									 "\\gset must follow an SQL command",
+									 cmd->first_line, -1);
+
+					/* get variable prefix */
+					if (command->argc <= 1 || command->argv[1][0] == '\0')
+						cmd->varprefix = pg_strdup("");
+					else
+						cmd->varprefix = pg_strdup(command->argv[1]);
+
+					/* update the sql command meta */
+					cmd->meta = command->meta;
+
+					/* cleanup unused command */
+					free_command(command);
+
+					continue;
+				}
+
+				/* Attach any other backslash command as a new command */
+				ps.commands[index++] = command;
+			}
+		}
+
+		/*
+		 * Since we used a command slot, allocate more if needed.  Note we
+		 * always allocate one more in order to accommodate the NULL
+		 * terminator below.
+		 */
+		if (index >= alloc_num)
+		{
+			alloc_num += COMMANDS_ALLOC_NUM;
+			ps.commands = (Command **)
+				pg_realloc(ps.commands, sizeof(Command *) * alloc_num);
+		}
+
+		/* Done if we reached EOF */
+		if (sr == PSCAN_INCOMPLETE || sr == PSCAN_EOL)
+			break;
+	}
+
+	ps.commands[index] = NULL;
+
+	addScript(ps);
+
+	termPQExpBuffer(&line_buf);
+	psql_scan_finish(sstate);
+	psql_scan_destroy(sstate);
+}
+
+/*
+ * Read the entire contents of file fd, and return it in a malloc'd buffer.
+ *
+ * The buffer will typically be larger than necessary, but we don't care
+ * in this program, because we'll free it as soon as we've parsed the script.
+ */
+static char *
+read_file_contents(FILE *fd)
+{
+	char	   *buf;
+	size_t		buflen = BUFSIZ;
+	size_t		used = 0;
+
+	buf = (char *) pg_malloc(buflen);
+
+	for (;;)
+	{
+		size_t		nread;
+
+		nread = fread(buf + used, 1, BUFSIZ, fd);
+		used += nread;
+		/* If fread() read less than requested, must be EOF or error */
+		if (nread < BUFSIZ)
+			break;
+		/* Enlarge buf so we can read some more */
+		buflen += BUFSIZ;
+		buf = (char *) pg_realloc(buf, buflen);
+	}
+	/* There is surely room for a terminator */
+	buf[used] = '\0';
+
+	return buf;
+}
+
+/*
+ * Given a file name, read it and add its script to the list.
+ * "-" means to read stdin.
+ * NB: filename must be storage that won't disappear.
+ */
+static void
+process_file(const char *filename, int weight)
+{
+	FILE	   *fd;
+	char	   *buf;
+
+	/* Slurp the file contents into "buf" */
+	if (strcmp(filename, "-") == 0)
+		fd = stdin;
+	else if ((fd = fopen(filename, "r")) == NULL)
+	{
+		pg_log_fatal("could not open file \"%s\": %m", filename);
+		exit(1);
+	}
+
+	buf = read_file_contents(fd);
+
+	if (ferror(fd))
+	{
+		pg_log_fatal("could not read file \"%s\": %m", filename);
+		exit(1);
+	}
+
+	if (fd != stdin)
+		fclose(fd);
+
+	ParseScript(buf, filename, weight);
+
+	free(buf);
+}
+
+/* Parse the given builtin script and add it to the list. */
+static void
+process_builtin(const BuiltinScript *bi, int weight)
+{
+	ParseScript(bi->script, bi->desc, weight);
+}
+
+/* show available builtin scripts */
+static void
+listAvailableScripts(void)
+{
+	int			i;
+
+	fprintf(stderr, "Available builtin scripts:\n");
+	for (i = 0; i < lengthof(builtin_script); i++)
+		fprintf(stderr, "  %13s: %s\n", builtin_script[i].name, builtin_script[i].desc);
+	fprintf(stderr, "\n");
+}
+
+/* return builtin script "name" if unambiguous, fails if not found */
+static const BuiltinScript *
+findBuiltin(const char *name)
+{
+	int			i,
+				found = 0,
+				len = strlen(name);
+	const BuiltinScript *result = NULL;
+
+	for (i = 0; i < lengthof(builtin_script); i++)
+	{
+		if (strncmp(builtin_script[i].name, name, len) == 0)
+		{
+			result = &builtin_script[i];
+			found++;
+		}
+	}
+
+	/* ok, unambiguous result */
+	if (found == 1)
+		return result;
+
+	/* error cases */
+	if (found == 0)
+		pg_log_fatal("no builtin script found for name \"%s\"", name);
+	else						/* found > 1 */
+		pg_log_fatal("ambiguous builtin name: %d builtin scripts found for prefix \"%s\"", found, name);
+
+	listAvailableScripts();
+	exit(1);
+}
+
+/*
+ * Determine the weight specification from a script option (-b, -f), if any,
+ * and return it as an integer (1 is returned if there's no weight).  The
+ * script name is returned in *script as a malloc'd string.
+ */
+static int
+parseScriptWeight(const char *option, char **script)
+{
+	char	   *sep;
+	int			weight;
+
+	if ((sep = strrchr(option, WSEP)))
+	{
+		int			namelen = sep - option;
+		long		wtmp;
+		char	   *badp;
+
+		/* generate the script name */
+		*script = pg_malloc(namelen + 1);
+		strncpy(*script, option, namelen);
+		(*script)[namelen] = '\0';
+
+		/* process digits of the weight spec */
+		errno = 0;
+		wtmp = strtol(sep + 1, &badp, 10);
+		if (errno != 0 || badp == sep + 1 || *badp != '\0')
+		{
+			pg_log_fatal("invalid weight specification: %s", sep);
+			exit(1);
+		}
+		if (wtmp > INT_MAX || wtmp < 0)
+		{
+			pg_log_fatal("weight specification out of range (0 .. %u): %lld",
+						 INT_MAX, (long long) wtmp);
+			exit(1);
+		}
+		weight = wtmp;
+	}
+	else
+	{
+		*script = pg_strdup(option);
+		weight = 1;
+	}
+
+	return weight;
+}
+
+/* append a script to the list of scripts to process */
+static void
+addScript(ParsedScript script)
+{
+	if (script.commands == NULL || script.commands[0] == NULL)
+	{
+		pg_log_fatal("empty command list for script \"%s\"", script.desc);
+		exit(1);
+	}
+
+	if (num_scripts >= MAX_SCRIPTS)
+	{
+		pg_log_fatal("at most %d SQL scripts are allowed", MAX_SCRIPTS);
+		exit(1);
+	}
+
+	CheckConditional(script);
+
+	sql_script[num_scripts] = script;
+	num_scripts++;
+}
+
+/*
+ * Print progress report.
+ *
+ * On entry, *last and *last_report contain the statistics and time of last
+ * progress report.  On exit, they are updated with the new stats.
+ */
+static void
+printProgressReport(TState *threads, int64 test_start, pg_time_usec_t now,
+					StatsData *last, int64 *last_report)
+{
+	/* generate and show report */
+	pg_time_usec_t run = now - *last_report;
+	int64		ntx;
+	double		tps,
+				total_run,
+				latency,
+				sqlat,
+				lag,
+				stdev;
+	char		tbuf[315];
+	StatsData	cur;
+
+	/*
+	 * Add up the statistics of all threads.
+	 *
+	 * XXX: No locking.  There is no guarantee that we get an atomic snapshot
+	 * of the transaction count and latencies, so these figures can well be
+	 * off by a small amount.  The progress report's purpose is to give a
+	 * quick overview of how the test is going, so that shouldn't matter too
+	 * much.  (If a read from a 64-bit integer is not atomic, you might get a
+	 * "torn" read and completely bogus latencies though!)
+	 */
+	initStats(&cur, 0);
+	for (int i = 0; i < nthreads; i++)
+	{
+		mergeSimpleStats(&cur.latency, &threads[i].stats.latency);
+		mergeSimpleStats(&cur.lag, &threads[i].stats.lag);
+		cur.cnt += threads[i].stats.cnt;
+		cur.skipped += threads[i].stats.skipped;
+	}
+
+	/* we count only actually executed transactions */
+	ntx = (cur.cnt - cur.skipped) - (last->cnt - last->skipped);
+	total_run = (now - test_start) / 1000000.0;
+	tps = 1000000.0 * ntx / run;
+	if (ntx > 0)
+	{
+		latency = 0.001 * (cur.latency.sum - last->latency.sum) / ntx;
+		sqlat = 1.0 * (cur.latency.sum2 - last->latency.sum2) / ntx;
+		stdev = 0.001 * sqrt(sqlat - 1000000.0 * latency * latency);
+		lag = 0.001 * (cur.lag.sum - last->lag.sum) / ntx;
+	}
+	else
+	{
+		latency = sqlat = stdev = lag = 0;
+	}
+
+	if (progress_timestamp)
+	{
+		snprintf(tbuf, sizeof(tbuf), "%.3f s",
+				 PG_TIME_GET_DOUBLE(now + epoch_shift));
+	}
+	else
+	{
+		/* round seconds are expected, but the thread may be late */
+		snprintf(tbuf, sizeof(tbuf), "%.1f s", total_run);
+	}
+
+	fprintf(stderr,
+			"progress: %s, %.1f tps, lat %.3f ms stddev %.3f",
+			tbuf, tps, latency, stdev);
+
+	if (throttle_delay)
+	{
+		fprintf(stderr, ", lag %.3f ms", lag);
+		if (latency_limit)
+			fprintf(stderr, ", " INT64_FORMAT " skipped",
+					cur.skipped - last->skipped);
+	}
+	fprintf(stderr, "\n");
+
+	*last = cur;
+	*last_report = now;
+}
+
+static void
+printSimpleStats(const char *prefix, SimpleStats *ss)
+{
+	if (ss->count > 0)
+	{
+		double		latency = ss->sum / ss->count;
+		double		stddev = sqrt(ss->sum2 / ss->count - latency * latency);
+
+		printf("%s average = %.3f ms\n", prefix, 0.001 * latency);
+		printf("%s stddev = %.3f ms\n", prefix, 0.001 * stddev);
+	}
+}
+
+/* print version banner */
+static void
+printVersion(PGconn *con)
+{
+	int			server_ver = PQserverVersion(con);
+	int			client_ver = PG_VERSION_NUM;
+
+	if (server_ver != client_ver)
+	{
+		const char *server_version;
+		char		sverbuf[32];
+
+		/* Try to get full text form, might include "devel" etc */
+		server_version = PQparameterStatus(con, "server_version");
+		/* Otherwise fall back on server_ver */
+		if (!server_version)
+		{
+			formatPGVersionNumber(server_ver, true,
+								  sverbuf, sizeof(sverbuf));
+			server_version = sverbuf;
+		}
+
+		printf(_("%s (%s, server %s)\n"),
+			   "pgbench", PG_VERSION, server_version);
+	}
+	/* For version match, only print pgbench version */
+	else
+		printf("%s (%s)\n", "pgbench", PG_VERSION);
+	fflush(stdout);
+}
+
+/* print out results */
+static void
+printResults(StatsData *total,
+			 pg_time_usec_t total_duration, /* benchmarking time */
+			 pg_time_usec_t conn_total_duration,	/* is_connect */
+			 pg_time_usec_t conn_elapsed_duration,	/* !is_connect */
+			 int64 latency_late)
+{
+	/* tps is about actually executed transactions during benchmarking */
+	int64		ntx = total->cnt - total->skipped;
+	double		bench_duration = PG_TIME_GET_DOUBLE(total_duration);
+	double		tps = ntx / bench_duration;
+
+	/* Report test parameters. */
+	printf("transaction type: %s\n",
+		   num_scripts == 1 ? sql_script[0].desc : "multiple scripts");
+	printf("scaling factor: %d\n", scale);
+	/* only print partitioning information if some partitioning was detected */
+	if (partition_method != PART_NONE)
+		printf("partition method: %s\npartitions: %d\n",
+			   PARTITION_METHOD[partition_method], partitions);
+	printf("query mode: %s\n", QUERYMODE[querymode]);
+	printf("number of clients: %d\n", nclients);
+	printf("number of threads: %d\n", nthreads);
+	if (duration <= 0)
+	{
+		printf("number of transactions per client: %d\n", nxacts);
+		printf("number of transactions actually processed: " INT64_FORMAT "/%d\n",
+			   ntx, nxacts * nclients);
+	}
+	else
+	{
+		printf("duration: %d s\n", duration);
+		printf("number of transactions actually processed: " INT64_FORMAT "\n",
+			   ntx);
+	}
+
+	/* Remaining stats are nonsensical if we failed to execute any xacts */
+	if (total->cnt <= 0)
+		return;
+
+	if (throttle_delay && latency_limit)
+		printf("number of transactions skipped: " INT64_FORMAT " (%.3f %%)\n",
+			   total->skipped, 100.0 * total->skipped / total->cnt);
+
+	if (latency_limit)
+		printf("number of transactions above the %.1f ms latency limit: " INT64_FORMAT "/" INT64_FORMAT " (%.3f %%)\n",
+			   latency_limit / 1000.0, latency_late, ntx,
+			   (ntx > 0) ? 100.0 * latency_late / ntx : 0.0);
+
+	if (throttle_delay || progress || latency_limit)
+		printSimpleStats("latency", &total->latency);
+	else
+	{
+		/* no measurement, show average latency computed from run time */
+		printf("latency average = %.3f ms\n",
+			   0.001 * total_duration * nclients / total->cnt);
+	}
+
+	if (throttle_delay)
+	{
+		/*
+		 * Report average transaction lag under rate limit throttling.  This
+		 * is the delay between scheduled and actual start times for the
+		 * transaction.  The measured lag may be caused by thread/client load,
+		 * the database load, or the Poisson throttling process.
+		 */
+		printf("rate limit schedule lag: avg %.3f (max %.3f) ms\n",
+			   0.001 * total->lag.sum / total->cnt, 0.001 * total->lag.max);
+	}
+
+	/*
+	 * Under -C/--connect, each transaction incurs a significant connection
+	 * cost, it would not make much sense to ignore it in tps, and it would
+	 * not be tps anyway.
+	 *
+	 * Otherwise connections are made just once at the beginning of the run
+	 * and should not impact performance but for very short run, so they are
+	 * (right)fully ignored in tps.
+	 */
+	if (is_connect)
+	{
+		printf("average connection time = %.3f ms\n", 0.001 * conn_total_duration / total->cnt);
+		printf("tps = %f (including reconnection times)\n", tps);
+	}
+	else
+	{
+		printf("initial connection time = %.3f ms\n", 0.001 * conn_elapsed_duration);
+		printf("tps = %f (without initial connection time)\n", tps);
+	}
+
+	/* Report per-script/command statistics */
+	if (per_script_stats || report_per_command)
+	{
+		int			i;
+
+		for (i = 0; i < num_scripts; i++)
+		{
+			if (per_script_stats)
+			{
+				StatsData  *sstats = &sql_script[i].stats;
+
+				printf("SQL script %d: %s\n"
+					   " - weight: %d (targets %.1f%% of total)\n"
+					   " - " INT64_FORMAT " transactions (%.1f%% of total, tps = %f)\n",
+					   i + 1, sql_script[i].desc,
+					   sql_script[i].weight,
+					   100.0 * sql_script[i].weight / total_weight,
+					   sstats->cnt,
+					   100.0 * sstats->cnt / total->cnt,
+					   (sstats->cnt - sstats->skipped) / bench_duration);
+
+				if (throttle_delay && latency_limit && sstats->cnt > 0)
+					printf(" - number of transactions skipped: " INT64_FORMAT " (%.3f%%)\n",
+						   sstats->skipped,
+						   100.0 * sstats->skipped / sstats->cnt);
+
+				printSimpleStats(" - latency", &sstats->latency);
+			}
+
+			/* Report per-command latencies */
+			if (report_per_command)
+			{
+				Command   **commands;
+
+				if (per_script_stats)
+					printf(" - statement latencies in milliseconds:\n");
+				else
+					printf("statement latencies in milliseconds:\n");
+
+				for (commands = sql_script[i].commands;
+					 *commands != NULL;
+					 commands++)
+				{
+					SimpleStats *cstats = &(*commands)->stats;
+
+					printf("   %11.3f  %s\n",
+						   (cstats->count > 0) ?
+						   1000.0 * cstats->sum / cstats->count : 0.0,
+						   (*commands)->first_line);
+				}
+			}
+		}
+	}
+}
+
+/*
+ * Set up a random seed according to seed parameter (NULL means default),
+ * and initialize base_random_sequence for use in initializing other sequences.
+ */
+static bool
+set_random_seed(const char *seed)
+{
+	uint64		iseed;
+
+	if (seed == NULL || strcmp(seed, "time") == 0)
+	{
+		/* rely on current time */
+		iseed = pg_time_now();
+	}
+	else if (strcmp(seed, "rand") == 0)
+	{
+		/* use some "strong" random source */
+		if (!pg_strong_random(&iseed, sizeof(iseed)))
+		{
+			pg_log_error("could not generate random seed");
+			return false;
+		}
+	}
+	else
+	{
+		/* parse unsigned-int seed value */
+		unsigned long ulseed;
+		char		garbage;
+
+		/* Don't try to use UINT64_FORMAT here; it might not work for sscanf */
+		if (sscanf(seed, "%lu%c", &ulseed, &garbage) != 1)
+		{
+			pg_log_error("unrecognized random seed option \"%s\"", seed);
+			pg_log_info("Expecting an unsigned integer, \"time\" or \"rand\"");
+			return false;
+		}
+		iseed = (uint64) ulseed;
+	}
+
+	if (seed != NULL)
+		pg_log_info("setting random seed to %llu", (unsigned long long) iseed);
+	random_seed = iseed;
+
+	/* Fill base_random_sequence with low-order bits of seed */
+	base_random_sequence.xseed[0] = iseed & 0xFFFF;
+	base_random_sequence.xseed[1] = (iseed >> 16) & 0xFFFF;
+	base_random_sequence.xseed[2] = (iseed >> 32) & 0xFFFF;
+
+	return true;
+}
+
+int
+main(int argc, char **argv)
+{
+	static struct option long_options[] = {
+		/* systematic long/short named options */
+		{"builtin", required_argument, NULL, 'b'},
+		{"client", required_argument, NULL, 'c'},
+		{"connect", no_argument, NULL, 'C'},
+		{"debug", no_argument, NULL, 'd'},
+		{"define", required_argument, NULL, 'D'},
+		{"file", required_argument, NULL, 'f'},
+		{"fillfactor", required_argument, NULL, 'F'},
+		{"host", required_argument, NULL, 'h'},
+		{"initialize", no_argument, NULL, 'i'},
+		{"init-steps", required_argument, NULL, 'I'},
+		{"jobs", required_argument, NULL, 'j'},
+		{"log", no_argument, NULL, 'l'},
+		{"latency-limit", required_argument, NULL, 'L'},
+		{"no-vacuum", no_argument, NULL, 'n'},
+		{"port", required_argument, NULL, 'p'},
+		{"progress", required_argument, NULL, 'P'},
+		{"protocol", required_argument, NULL, 'M'},
+		{"quiet", no_argument, NULL, 'q'},
+		{"report-latencies", no_argument, NULL, 'r'},
+		{"rate", required_argument, NULL, 'R'},
+		{"scale", required_argument, NULL, 's'},
+		{"select-only", no_argument, NULL, 'S'},
+		{"skip-some-updates", no_argument, NULL, 'N'},
+		{"time", required_argument, NULL, 'T'},
+		{"transactions", required_argument, NULL, 't'},
+		{"username", required_argument, NULL, 'U'},
+		{"vacuum-all", no_argument, NULL, 'v'},
+		/* long-named only options */
+		{"unlogged-tables", no_argument, NULL, 1},
+		{"tablespace", required_argument, NULL, 2},
+		{"index-tablespace", required_argument, NULL, 3},
+		{"sampling-rate", required_argument, NULL, 4},
+		{"aggregate-interval", required_argument, NULL, 5},
+		{"progress-timestamp", no_argument, NULL, 6},
+		{"log-prefix", required_argument, NULL, 7},
+		{"foreign-keys", no_argument, NULL, 8},
+		{"random-seed", required_argument, NULL, 9},
+		{"show-script", required_argument, NULL, 10},
+		{"partitions", required_argument, NULL, 11},
+		{"partition-method", required_argument, NULL, 12},
+		{NULL, 0, NULL, 0}
+	};
+
+	int			c;
+	bool		is_init_mode = false;	/* initialize mode? */
+	char	   *initialize_steps = NULL;
+	bool		foreign_keys = false;
+	bool		is_no_vacuum = false;
+	bool		do_vacuum_accounts = false; /* vacuum accounts table? */
+	int			optindex;
+	bool		scale_given = false;
+
+	bool		benchmarking_option_set = false;
+	bool		initialization_option_set = false;
+	bool		internal_script_used = false;
+
+	CState	   *state;			/* status of clients */
+	TState	   *threads;		/* array of thread */
+
+	pg_time_usec_t
+				start_time,		/* start up time */
+				bench_start = 0,	/* first recorded benchmarking time */
+				conn_total_duration;	/* cumulated connection time in
+										 * threads */
+	int64		latency_late = 0;
+	StatsData	stats;
+	int			weight;
+
+	int			i;
+	int			nclients_dealt;
+
+#ifdef HAVE_GETRLIMIT
+	struct rlimit rlim;
+#endif
+
+	PGconn	   *con;
+	char	   *env;
+
+	int			exit_code = 0;
+	struct timeval tv;
+
+	/*
+	 * Record difference between Unix time and instr_time time.  We'll use
+	 * this for logging and aggregation.
+	 */
+	gettimeofday(&tv, NULL);
+	epoch_shift = tv.tv_sec * INT64CONST(1000000) + tv.tv_usec - pg_time_now();
+
+	pg_logging_init(argv[0]);
+	progname = get_progname(argv[0]);
+
+	if (argc > 1)
+	{
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
+		{
+			usage();
+			exit(0);
+		}
+		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
+		{
+			puts("pgbench (PostgreSQL) " PG_VERSION);
+			exit(0);
+		}
+	}
+
+	state = (CState *) pg_malloc0(sizeof(CState));
+
+	/* set random seed early, because it may be used while parsing scripts. */
+	if (!set_random_seed(getenv("PGBENCH_RANDOM_SEED")))
+	{
+		pg_log_fatal("error while setting random seed from PGBENCH_RANDOM_SEED environment variable");
+		exit(1);
+	}
+
+	while ((c = getopt_long(argc, argv, "iI:h:nvp:dqb:SNc:j:Crs:t:T:U:lf:D:F:M:P:R:L:", long_options, &optindex)) != -1)
+	{
+		char	   *script;
+
+		switch (c)
+		{
+			case 'i':
+				is_init_mode = true;
+				break;
+			case 'I':
+				if (initialize_steps)
+					pg_free(initialize_steps);
+				initialize_steps = pg_strdup(optarg);
+				checkInitSteps(initialize_steps);
+				initialization_option_set = true;
+				break;
+			case 'h':
+				pghost = pg_strdup(optarg);
+				break;
+			case 'n':
+				is_no_vacuum = true;
+				break;
+			case 'v':
+				benchmarking_option_set = true;
+				do_vacuum_accounts = true;
+				break;
+			case 'p':
+				pgport = pg_strdup(optarg);
+				break;
+			case 'd':
+				pg_logging_increase_verbosity();
+				break;
+			case 'c':
+				benchmarking_option_set = true;
+				nclients = atoi(optarg);
+				if (nclients <= 0)
+				{
+					pg_log_fatal("invalid number of clients: \"%s\"", optarg);
+					exit(1);
+				}
+#ifdef HAVE_GETRLIMIT
+#ifdef RLIMIT_NOFILE			/* most platforms use RLIMIT_NOFILE */
+				if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
+#else							/* but BSD doesn't ... */
+				if (getrlimit(RLIMIT_OFILE, &rlim) == -1)
+#endif							/* RLIMIT_NOFILE */
+				{
+					pg_log_fatal("getrlimit failed: %m");
+					exit(1);
+				}
+				if (rlim.rlim_cur < nclients + 3)
+				{
+					pg_log_fatal("need at least %d open files, but system limit is %ld",
+								 nclients + 3, (long) rlim.rlim_cur);
+					pg_log_info("Reduce number of clients, or use limit/ulimit to increase the system limit.");
+					exit(1);
+				}
+#endif							/* HAVE_GETRLIMIT */
+				break;
+			case 'j':			/* jobs */
+				benchmarking_option_set = true;
+				nthreads = atoi(optarg);
+				if (nthreads <= 0)
+				{
+					pg_log_fatal("invalid number of threads: \"%s\"", optarg);
+					exit(1);
+				}
+#ifndef ENABLE_THREAD_SAFETY
+				if (nthreads != 1)
+				{
+					pg_log_fatal("threads are not supported on this platform; use -j1");
+					exit(1);
+				}
+#endif							/* !ENABLE_THREAD_SAFETY */
+				break;
+			case 'C':
+				benchmarking_option_set = true;
+				is_connect = true;
+				break;
+			case 'r':
+				benchmarking_option_set = true;
+				report_per_command = true;
+				break;
+			case 's':
+				scale_given = true;
+				scale = atoi(optarg);
+				if (scale <= 0)
+				{
+					pg_log_fatal("invalid scaling factor: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 't':
+				benchmarking_option_set = true;
+				nxacts = atoi(optarg);
+				if (nxacts <= 0)
+				{
+					pg_log_fatal("invalid number of transactions: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 'T':
+				benchmarking_option_set = true;
+				duration = atoi(optarg);
+				if (duration <= 0)
+				{
+					pg_log_fatal("invalid duration: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 'U':
+				username = pg_strdup(optarg);
+				break;
+			case 'l':
+				benchmarking_option_set = true;
+				use_log = true;
+				break;
+			case 'q':
+				initialization_option_set = true;
+				use_quiet = true;
+				break;
+			case 'b':
+				if (strcmp(optarg, "list") == 0)
+				{
+					listAvailableScripts();
+					exit(0);
+				}
+				weight = parseScriptWeight(optarg, &script);
+				process_builtin(findBuiltin(script), weight);
+				benchmarking_option_set = true;
+				internal_script_used = true;
+				break;
+			case 'S':
+				process_builtin(findBuiltin("select-only"), 1);
+				benchmarking_option_set = true;
+				internal_script_used = true;
+				break;
+			case 'N':
+				process_builtin(findBuiltin("simple-update"), 1);
+				benchmarking_option_set = true;
+				internal_script_used = true;
+				break;
+			case 'f':
+				weight = parseScriptWeight(optarg, &script);
+				process_file(script, weight);
+				benchmarking_option_set = true;
+				break;
+			case 'D':
+				{
+					char	   *p;
+
+					benchmarking_option_set = true;
+
+					if ((p = strchr(optarg, '=')) == NULL || p == optarg || *(p + 1) == '\0')
+					{
+						pg_log_fatal("invalid variable definition: \"%s\"", optarg);
+						exit(1);
+					}
+
+					*p++ = '\0';
+					if (!putVariable(&state[0], "option", optarg, p))
+						exit(1);
+				}
+				break;
+			case 'F':
+				initialization_option_set = true;
+				fillfactor = atoi(optarg);
+				if (fillfactor < 10 || fillfactor > 100)
+				{
+					pg_log_fatal("invalid fillfactor: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 'M':
+				benchmarking_option_set = true;
+				for (querymode = 0; querymode < NUM_QUERYMODE; querymode++)
+					if (strcmp(optarg, QUERYMODE[querymode]) == 0)
+						break;
+				if (querymode >= NUM_QUERYMODE)
+				{
+					pg_log_fatal("invalid query mode (-M): \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 'P':
+				benchmarking_option_set = true;
+				progress = atoi(optarg);
+				if (progress <= 0)
+				{
+					pg_log_fatal("invalid thread progress delay: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 'R':
+				{
+					/* get a double from the beginning of option value */
+					double		throttle_value = atof(optarg);
+
+					benchmarking_option_set = true;
+
+					if (throttle_value <= 0.0)
+					{
+						pg_log_fatal("invalid rate limit: \"%s\"", optarg);
+						exit(1);
+					}
+					/* Invert rate limit into per-transaction delay in usec */
+					throttle_delay = 1000000.0 / throttle_value;
+				}
+				break;
+			case 'L':
+				{
+					double		limit_ms = atof(optarg);
+
+					if (limit_ms <= 0.0)
+					{
+						pg_log_fatal("invalid latency limit: \"%s\"", optarg);
+						exit(1);
+					}
+					benchmarking_option_set = true;
+					latency_limit = (int64) (limit_ms * 1000);
+				}
+				break;
+			case 1:				/* unlogged-tables */
+				initialization_option_set = true;
+				unlogged_tables = true;
+				break;
+			case 2:				/* tablespace */
+				initialization_option_set = true;
+				tablespace = pg_strdup(optarg);
+				break;
+			case 3:				/* index-tablespace */
+				initialization_option_set = true;
+				index_tablespace = pg_strdup(optarg);
+				break;
+			case 4:				/* sampling-rate */
+				benchmarking_option_set = true;
+				sample_rate = atof(optarg);
+				if (sample_rate <= 0.0 || sample_rate > 1.0)
+				{
+					pg_log_fatal("invalid sampling rate: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 5:				/* aggregate-interval */
+				benchmarking_option_set = true;
+				agg_interval = atoi(optarg);
+				if (agg_interval <= 0)
+				{
+					pg_log_fatal("invalid number of seconds for aggregation: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 6:				/* progress-timestamp */
+				progress_timestamp = true;
+				benchmarking_option_set = true;
+				break;
+			case 7:				/* log-prefix */
+				benchmarking_option_set = true;
+				logfile_prefix = pg_strdup(optarg);
+				break;
+			case 8:				/* foreign-keys */
+				initialization_option_set = true;
+				foreign_keys = true;
+				break;
+			case 9:				/* random-seed */
+				benchmarking_option_set = true;
+				if (!set_random_seed(optarg))
+				{
+					pg_log_fatal("error while setting random seed from --random-seed option");
+					exit(1);
+				}
+				break;
+			case 10:			/* list */
+				{
+					const BuiltinScript *s = findBuiltin(optarg);
+
+					fprintf(stderr, "-- %s: %s\n%s\n", s->name, s->desc, s->script);
+					exit(0);
+				}
+				break;
+			case 11:			/* partitions */
+				initialization_option_set = true;
+				partitions = atoi(optarg);
+				if (partitions < 0)
+				{
+					pg_log_fatal("invalid number of partitions: \"%s\"", optarg);
+					exit(1);
+				}
+				break;
+			case 12:			/* partition-method */
+				initialization_option_set = true;
+				if (pg_strcasecmp(optarg, "range") == 0)
+					partition_method = PART_RANGE;
+				else if (pg_strcasecmp(optarg, "hash") == 0)
+					partition_method = PART_HASH;
+				else
+				{
+					pg_log_fatal("invalid partition method, expecting \"range\" or \"hash\", got: \"%s\"",
+								 optarg);
+					exit(1);
+				}
+				break;
+			default:
+				fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
+				exit(1);
+				break;
+		}
+	}
+
+	/* set default script if none */
+	if (num_scripts == 0 && !is_init_mode)
+	{
+		process_builtin(findBuiltin("tpcb-like"), 1);
+		benchmarking_option_set = true;
+		internal_script_used = true;
+	}
+
+	/* complete SQL command initialization and compute total weight */
+	for (i = 0; i < num_scripts; i++)
+	{
+		Command   **commands = sql_script[i].commands;
+
+		for (int j = 0; commands[j] != NULL; j++)
+			if (commands[j]->type == SQL_COMMAND)
+				postprocess_sql_command(commands[j]);
+
+		/* cannot overflow: weight is 32b, total_weight 64b */
+		total_weight += sql_script[i].weight;
+	}
+
+	if (total_weight == 0 && !is_init_mode)
+	{
+		pg_log_fatal("total script weight must not be zero");
+		exit(1);
+	}
+
+	/* show per script stats if several scripts are used */
+	if (num_scripts > 1)
+		per_script_stats = true;
+
+	/*
+	 * Don't need more threads than there are clients.  (This is not merely an
+	 * optimization; throttle_delay is calculated incorrectly below if some
+	 * threads have no clients assigned to them.)
+	 */
+	if (nthreads > nclients)
+		nthreads = nclients;
+
+	/*
+	 * Convert throttle_delay to a per-thread delay time.  Note that this
+	 * might be a fractional number of usec, but that's OK, since it's just
+	 * the center of a Poisson distribution of delays.
+	 */
+	throttle_delay *= nthreads;
+
+	if (argc > optind)
+		dbName = argv[optind++];
+	else
+	{
+		if ((env = getenv("PGDATABASE")) != NULL && *env != '\0')
+			dbName = env;
+		else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
+			dbName = env;
+		else
+			dbName = get_user_name_or_exit(progname);
+	}
+
+	if (optind < argc)
+	{
+		pg_log_fatal("too many command-line arguments (first is \"%s\")",
+					 argv[optind]);
+		fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
+		exit(1);
+	}
+
+	if (is_init_mode)
+	{
+		if (benchmarking_option_set)
+		{
+			pg_log_fatal("some of the specified options cannot be used in initialization (-i) mode");
+			exit(1);
+		}
+
+		if (partitions == 0 && partition_method != PART_NONE)
+		{
+			pg_log_fatal("--partition-method requires greater than zero --partitions");
+			exit(1);
+		}
+
+		/* set default method */
+		if (partitions > 0 && partition_method == PART_NONE)
+			partition_method = PART_RANGE;
+
+		if (initialize_steps == NULL)
+			initialize_steps = pg_strdup(DEFAULT_INIT_STEPS);
+
+		if (is_no_vacuum)
+		{
+			/* Remove any vacuum step in initialize_steps */
+			char	   *p;
+
+			while ((p = strchr(initialize_steps, 'v')) != NULL)
+				*p = ' ';
+		}
+
+		if (foreign_keys)
+		{
+			/* Add 'f' to end of initialize_steps, if not already there */
+			if (strchr(initialize_steps, 'f') == NULL)
+			{
+				initialize_steps = (char *)
+					pg_realloc(initialize_steps,
+							   strlen(initialize_steps) + 2);
+				strcat(initialize_steps, "f");
+			}
+		}
+
+		runInitSteps(initialize_steps);
+		exit(0);
+	}
+	else
+	{
+		if (initialization_option_set)
+		{
+			pg_log_fatal("some of the specified options cannot be used in benchmarking mode");
+			exit(1);
+		}
+	}
+
+	if (nxacts > 0 && duration > 0)
+	{
+		pg_log_fatal("specify either a number of transactions (-t) or a duration (-T), not both");
+		exit(1);
+	}
+
+	/* Use DEFAULT_NXACTS if neither nxacts nor duration is specified. */
+	if (nxacts <= 0 && duration <= 0)
+		nxacts = DEFAULT_NXACTS;
+
+	/* --sampling-rate may be used only with -l */
+	if (sample_rate > 0.0 && !use_log)
+	{
+		pg_log_fatal("log sampling (--sampling-rate) is allowed only when logging transactions (-l)");
+		exit(1);
+	}
+
+	/* --sampling-rate may not be used with --aggregate-interval */
+	if (sample_rate > 0.0 && agg_interval > 0)
+	{
+		pg_log_fatal("log sampling (--sampling-rate) and aggregation (--aggregate-interval) cannot be used at the same time");
+		exit(1);
+	}
+
+	if (agg_interval > 0 && !use_log)
+	{
+		pg_log_fatal("log aggregation is allowed only when actually logging transactions");
+		exit(1);
+	}
+
+	if (!use_log && logfile_prefix)
+	{
+		pg_log_fatal("log file prefix (--log-prefix) is allowed only when logging transactions (-l)");
+		exit(1);
+	}
+
+	if (duration > 0 && agg_interval > duration)
+	{
+		pg_log_fatal("number of seconds for aggregation (%d) must not be higher than test duration (%d)", agg_interval, duration);
+		exit(1);
+	}
+
+	if (duration > 0 && agg_interval > 0 && duration % agg_interval != 0)
+	{
+		pg_log_fatal("duration (%d) must be a multiple of aggregation interval (%d)", duration, agg_interval);
+		exit(1);
+	}
+
+	if (progress_timestamp && progress == 0)
+	{
+		pg_log_fatal("--progress-timestamp is allowed only under --progress");
+		exit(1);
+	}
+
+	/*
+	 * save main process id in the global variable because process id will be
+	 * changed after fork.
+	 */
+	main_pid = (int) getpid();
+
+	if (nclients > 1)
+	{
+		state = (CState *) pg_realloc(state, sizeof(CState) * nclients);
+		memset(state + 1, 0, sizeof(CState) * (nclients - 1));
+
+		/* copy any -D switch values to all clients */
+		for (i = 1; i < nclients; i++)
+		{
+			int			j;
+
+			state[i].id = i;
+			for (j = 0; j < state[0].nvariables; j++)
+			{
+				Variable   *var = &state[0].variables[j];
+
+				if (var->value.type != PGBT_NO_VALUE)
+				{
+					if (!putVariableValue(&state[i], "startup",
+										  var->name, &var->value))
+						exit(1);
+				}
+				else
+				{
+					if (!putVariable(&state[i], "startup",
+									 var->name, var->svalue))
+						exit(1);
+				}
+			}
+		}
+	}
+
+	/* other CState initializations */
+	for (i = 0; i < nclients; i++)
+	{
+		state[i].cstack = conditional_stack_create();
+		initRandomState(&state[i].cs_func_rs);
+	}
+
+	/* opening connection... */
+	con = doConnect();
+	if (con == NULL)
+		exit(1);
+
+	/* report pgbench and server versions */
+	printVersion(con);
+
+	pg_log_debug("pghost: %s pgport: %s nclients: %d %s: %d dbName: %s",
+				 PQhost(con), PQport(con), nclients,
+				 duration <= 0 ? "nxacts" : "duration",
+				 duration <= 0 ? nxacts : duration, PQdb(con));
+
+	if (internal_script_used)
+		GetTableInfo(con, scale_given);
+
+	/*
+	 * :scale variables normally get -s or database scale, but don't override
+	 * an explicit -D switch
+	 */
+	if (lookupVariable(&state[0], "scale") == NULL)
+	{
+		for (i = 0; i < nclients; i++)
+		{
+			if (!putVariableInt(&state[i], "startup", "scale", scale))
+				exit(1);
+		}
+	}
+
+	/*
+	 * Define a :client_id variable that is unique per connection. But don't
+	 * override an explicit -D switch.
+	 */
+	if (lookupVariable(&state[0], "client_id") == NULL)
+	{
+		for (i = 0; i < nclients; i++)
+			if (!putVariableInt(&state[i], "startup", "client_id", i))
+				exit(1);
+	}
+
+	/* set default seed for hash functions */
+	if (lookupVariable(&state[0], "default_seed") == NULL)
+	{
+		uint64		seed =
+		((uint64) pg_jrand48(base_random_sequence.xseed) & 0xFFFFFFFF) |
+		(((uint64) pg_jrand48(base_random_sequence.xseed) & 0xFFFFFFFF) << 32);
+
+		for (i = 0; i < nclients; i++)
+			if (!putVariableInt(&state[i], "startup", "default_seed", (int64) seed))
+				exit(1);
+	}
+
+	/* set random seed unless overwritten */
+	if (lookupVariable(&state[0], "random_seed") == NULL)
+	{
+		for (i = 0; i < nclients; i++)
+			if (!putVariableInt(&state[i], "startup", "random_seed", random_seed))
+				exit(1);
+	}
+
+	if (!is_no_vacuum)
+	{
+		fprintf(stderr, "starting vacuum...");
+		tryExecuteStatement(con, "vacuum pgbench_branches");
+		tryExecuteStatement(con, "vacuum pgbench_tellers");
+		tryExecuteStatement(con, "truncate pgbench_history");
+		fprintf(stderr, "end.\n");
+
+		if (do_vacuum_accounts)
+		{
+			fprintf(stderr, "starting vacuum pgbench_accounts...");
+			tryExecuteStatement(con, "vacuum analyze pgbench_accounts");
+			fprintf(stderr, "end.\n");
+		}
+	}
+	PQfinish(con);
+
+	/* set up thread data structures */
+	threads = (TState *) pg_malloc(sizeof(TState) * nthreads);
+	nclients_dealt = 0;
+
+	for (i = 0; i < nthreads; i++)
+	{
+		TState	   *thread = &threads[i];
+
+		thread->tid = i;
+		thread->state = &state[nclients_dealt];
+		thread->nstate =
+			(nclients - nclients_dealt + nthreads - i - 1) / (nthreads - i);
+		initRandomState(&thread->ts_choose_rs);
+		initRandomState(&thread->ts_throttle_rs);
+		initRandomState(&thread->ts_sample_rs);
+		thread->logfile = NULL; /* filled in later */
+		thread->latency_late = 0;
+		initStats(&thread->stats, 0);
+
+		nclients_dealt += thread->nstate;
+	}
+
+	/* all clients must be assigned to a thread */
+	Assert(nclients_dealt == nclients);
+
+	/* get start up time for the whole computation */
+	start_time = pg_time_now();
+
+	/* set alarm if duration is specified. */
+	if (duration > 0)
+		setalarm(duration);
+
+	errno = THREAD_BARRIER_INIT(&barrier, nthreads);
+	if (errno != 0)
+		pg_log_fatal("could not initialize barrier: %m");
+
+#ifdef ENABLE_THREAD_SAFETY
+	/* start all threads but thread 0 which is executed directly later */
+	for (i = 1; i < nthreads; i++)
+	{
+		TState	   *thread = &threads[i];
+
+		thread->create_time = pg_time_now();
+		errno = THREAD_CREATE(&thread->thread, threadRun, thread);
+
+		if (errno != 0)
+		{
+			pg_log_fatal("could not create thread: %m");
+			exit(1);
+		}
+	}
+#else
+	Assert(nthreads == 1);
+#endif							/* ENABLE_THREAD_SAFETY */
+
+	/* compute when to stop */
+	threads[0].create_time = pg_time_now();
+	if (duration > 0)
+		end_time = threads[0].create_time + (int64) 1000000 * duration;
+
+	/* run thread 0 directly */
+	(void) threadRun(&threads[0]);
+
+	/* wait for other threads and accumulate results */
+	initStats(&stats, 0);
+	conn_total_duration = 0;
+
+	for (i = 0; i < nthreads; i++)
+	{
+		TState	   *thread = &threads[i];
+
+#ifdef ENABLE_THREAD_SAFETY
+		if (i > 0)
+			THREAD_JOIN(thread->thread);
+#endif							/* ENABLE_THREAD_SAFETY */
+
+		for (int j = 0; j < thread->nstate; j++)
+			if (thread->state[j].state != CSTATE_FINISHED)
+				exit_code = 2;
+
+		/* aggregate thread level stats */
+		mergeSimpleStats(&stats.latency, &thread->stats.latency);
+		mergeSimpleStats(&stats.lag, &thread->stats.lag);
+		stats.cnt += thread->stats.cnt;
+		stats.skipped += thread->stats.skipped;
+		latency_late += thread->latency_late;
+		conn_total_duration += thread->conn_duration;
+
+		/* first recorded benchmarking start time */
+		if (bench_start == 0 || thread->bench_start < bench_start)
+			bench_start = thread->bench_start;
+	}
+
+	/*
+	 * All connections should be already closed in threadRun(), so this
+	 * disconnect_all() will be a no-op, but clean up the connecions just to
+	 * be sure. We don't need to measure the disconnection delays here.
+	 */
+	disconnect_all(state, nclients);
+
+	/*
+	 * Beware that performance of short benchmarks with many threads and
+	 * possibly long transactions can be deceptive because threads do not
+	 * start and finish at the exact same time. The total duration computed
+	 * here encompasses all transactions so that tps shown is somehow slightly
+	 * underestimated.
+	 */
+	printResults(&stats, pg_time_now() - bench_start, conn_total_duration,
+				 bench_start - start_time, latency_late);
+
+	THREAD_BARRIER_DESTROY(&barrier);
+
+	if (exit_code != 0)
+		pg_log_fatal("Run was aborted; the above results are incomplete.");
+
+	return exit_code;
+}
+
+static THREAD_FUNC_RETURN_TYPE THREAD_FUNC_CC
+threadRun(void *arg)
+{
+	TState	   *thread = (TState *) arg;
+	CState	   *state = thread->state;
+	pg_time_usec_t start;
+	int			nstate = thread->nstate;
+	int			remains = nstate;	/* number of remaining clients */
+	socket_set *sockets = alloc_socket_set(nstate);
+	int64		thread_start,
+				last_report,
+				next_report;
+	StatsData	last,
+				aggs;
+
+	/* open log file if requested */
+	if (use_log)
+	{
+		char		logpath[MAXPGPATH];
+		char	   *prefix = logfile_prefix ? logfile_prefix : "pgbench_log";
+
+		if (thread->tid == 0)
+			snprintf(logpath, sizeof(logpath), "%s.%d", prefix, main_pid);
+		else
+			snprintf(logpath, sizeof(logpath), "%s.%d.%d", prefix, main_pid, thread->tid);
+
+		thread->logfile = fopen(logpath, "w");
+
+		if (thread->logfile == NULL)
+		{
+			pg_log_fatal("could not open logfile \"%s\": %m", logpath);
+			goto done;
+		}
+	}
+
+	/* explicitly initialize the state machines */
+	for (int i = 0; i < nstate; i++)
+		state[i].state = CSTATE_CHOOSE_SCRIPT;
+
+	/* READY */
+	THREAD_BARRIER_WAIT(&barrier);
+
+	thread_start = pg_time_now();
+	thread->started_time = thread_start;
+	thread->conn_duration = 0;
+	last_report = thread_start;
+	next_report = last_report + (int64) 1000000 * progress;
+
+	/* STEADY */
+	if (!is_connect)
+	{
+		/* make connections to the database before starting */
+		for (int i = 0; i < nstate; i++)
+		{
+			if ((state[i].con = doConnect()) == NULL)
+			{
+				/*
+				 * On connection failure, we meet the barrier here in place of
+				 * GO before proceeding to the "done" path which will cleanup,
+				 * so as to avoid locking the process.
+				 *
+				 * It is unclear whether it is worth doing anything rather
+				 * than coldly exiting with an error message.
+				 */
+				THREAD_BARRIER_WAIT(&barrier);
+				goto done;
+			}
+		}
+	}
+
+	/* GO */
+	THREAD_BARRIER_WAIT(&barrier);
+
+	start = pg_time_now();
+	thread->bench_start = start;
+	thread->throttle_trigger = start;
+
+	/*
+	 * The log format currently has Unix epoch timestamps with whole numbers
+	 * of seconds.  Round the first aggregate's start time down to the nearest
+	 * Unix epoch second (the very first aggregate might really have started a
+	 * fraction of a second later, but later aggregates are measured from the
+	 * whole number time that is actually logged).
+	 */
+	initStats(&aggs, (start + epoch_shift) / 1000000 * 1000000);
+	last = aggs;
+
+	/* loop till all clients have terminated */
+	while (remains > 0)
+	{
+		int			nsocks;		/* number of sockets to be waited for */
+		pg_time_usec_t min_usec;
+		pg_time_usec_t now = 0; /* set this only if needed */
+
+		/*
+		 * identify which client sockets should be checked for input, and
+		 * compute the nearest time (if any) at which we need to wake up.
+		 */
+		clear_socket_set(sockets);
+		nsocks = 0;
+		min_usec = PG_INT64_MAX;
+		for (int i = 0; i < nstate; i++)
+		{
+			CState	   *st = &state[i];
+
+			if (st->state == CSTATE_SLEEP || st->state == CSTATE_THROTTLE)
+			{
+				/* a nap from the script, or under throttling */
+				pg_time_usec_t this_usec;
+
+				/* get current time if needed */
+				pg_time_now_lazy(&now);
+
+				/* min_usec should be the minimum delay across all clients */
+				this_usec = (st->state == CSTATE_SLEEP ?
+							 st->sleep_until : st->txn_scheduled) - now;
+				if (min_usec > this_usec)
+					min_usec = this_usec;
+			}
+			else if (st->state == CSTATE_WAIT_RESULT)
+			{
+				/*
+				 * waiting for result from server - nothing to do unless the
+				 * socket is readable
+				 */
+				int			sock = PQsocket(st->con);
+
+				if (sock < 0)
+				{
+					pg_log_error("invalid socket: %s", PQerrorMessage(st->con));
+					goto done;
+				}
+
+				add_socket_to_set(sockets, sock, nsocks++);
+			}
+			else if (st->state != CSTATE_ABORTED &&
+					 st->state != CSTATE_FINISHED)
+			{
+				/*
+				 * This client thread is ready to do something, so we don't
+				 * want to wait.  No need to examine additional clients.
+				 */
+				min_usec = 0;
+				break;
+			}
+		}
+
+		/* also wake up to print the next progress report on time */
+		if (progress && min_usec > 0 && thread->tid == 0)
+		{
+			pg_time_now_lazy(&now);
+
+			if (now >= next_report)
+				min_usec = 0;
+			else if ((next_report - now) < min_usec)
+				min_usec = next_report - now;
+		}
+
+		/*
+		 * If no clients are ready to execute actions, sleep until we receive
+		 * data on some client socket or the timeout (if any) elapses.
+		 */
+		if (min_usec > 0)
+		{
+			int			rc = 0;
+
+			if (min_usec != PG_INT64_MAX)
+			{
+				if (nsocks > 0)
+				{
+					rc = wait_on_socket_set(sockets, min_usec);
+				}
+				else			/* nothing active, simple sleep */
+				{
+					pg_usleep(min_usec);
+				}
+			}
+			else				/* no explicit delay, wait without timeout */
+			{
+				rc = wait_on_socket_set(sockets, 0);
+			}
+
+			if (rc < 0)
+			{
+				if (errno == EINTR)
+				{
+					/* On EINTR, go back to top of loop */
+					continue;
+				}
+				/* must be something wrong */
+				pg_log_error("%s() failed: %m", SOCKET_WAIT_METHOD);
+				goto done;
+			}
+		}
+		else
+		{
+			/* min_usec <= 0, i.e. something needs to be executed now */
+
+			/* If we didn't wait, don't try to read any data */
+			clear_socket_set(sockets);
+		}
+
+		/* ok, advance the state machine of each connection */
+		nsocks = 0;
+		for (int i = 0; i < nstate; i++)
+		{
+			CState	   *st = &state[i];
+
+			if (st->state == CSTATE_WAIT_RESULT)
+			{
+				/* don't call advanceConnectionState unless data is available */
+				int			sock = PQsocket(st->con);
+
+				if (sock < 0)
+				{
+					pg_log_error("invalid socket: %s", PQerrorMessage(st->con));
+					goto done;
+				}
+
+				if (!socket_has_input(sockets, sock, nsocks++))
+					continue;
+			}
+			else if (st->state == CSTATE_FINISHED ||
+					 st->state == CSTATE_ABORTED)
+			{
+				/* this client is done, no need to consider it anymore */
+				continue;
+			}
+
+			advanceConnectionState(thread, st, &aggs);
+
+			/*
+			 * If advanceConnectionState changed client to finished state,
+			 * that's one fewer client that remains.
+			 */
+			if (st->state == CSTATE_FINISHED || st->state == CSTATE_ABORTED)
+				remains--;
+		}
+
+		/* progress report is made by thread 0 for all threads */
+		if (progress && thread->tid == 0)
+		{
+			pg_time_usec_t now = pg_time_now();
+
+			if (now >= next_report)
+			{
+				/*
+				 * Horrible hack: this relies on the thread pointer we are
+				 * passed to be equivalent to threads[0], that is the first
+				 * entry of the threads array.  That is why this MUST be done
+				 * by thread 0 and not any other.
+				 */
+				printProgressReport(thread, thread_start, now,
+									&last, &last_report);
+
+				/*
+				 * Ensure that the next report is in the future, in case
+				 * pgbench/postgres got stuck somewhere.
+				 */
+				do
+				{
+					next_report += (int64) 1000000 * progress;
+				} while (now >= next_report);
+			}
+		}
+	}
+
+done:
+	disconnect_all(state, nstate);
+
+	if (thread->logfile)
+	{
+		if (agg_interval > 0)
+		{
+			/* log aggregated but not yet reported transactions */
+			doLog(thread, state, &aggs, false, 0, 0);
+		}
+		fclose(thread->logfile);
+		thread->logfile = NULL;
+	}
+	free_socket_set(sockets);
+	THREAD_FUNC_RETURN;
+}
+
+static void
+finishCon(CState *st)
+{
+	if (st->con != NULL)
+	{
+		PQfinish(st->con);
+		st->con = NULL;
+	}
+}
+
+/*
+ * Support for duration option: set timer_exceeded after so many seconds.
+ */
+
+#ifndef WIN32
+
+static void
+handle_sig_alarm(SIGNAL_ARGS)
+{
+	timer_exceeded = true;
+}
+
+static void
+setalarm(int seconds)
+{
+	pqsignal(SIGALRM, handle_sig_alarm);
+	alarm(seconds);
+}
+
+#else							/* WIN32 */
+
+static VOID CALLBACK
+win32_timer_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
+{
+	timer_exceeded = true;
+}
+
+static void
+setalarm(int seconds)
+{
+	HANDLE		queue;
+	HANDLE		timer;
+
+	/* This function will be called at most once, so we can cheat a bit. */
+	queue = CreateTimerQueue();
+	if (seconds > ((DWORD) -1) / 1000 ||
+		!CreateTimerQueueTimer(&timer, queue,
+							   win32_timer_callback, NULL, seconds * 1000, 0,
+							   WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE))
+	{
+		pg_log_fatal("failed to set timer");
+		exit(1);
+	}
+}
+
+#endif							/* WIN32 */
+
+
+/*
+ * These functions provide an abstraction layer that hides the syscall
+ * we use to wait for input on a set of sockets.
+ *
+ * Currently there are two implementations, based on ppoll(2) and select(2).
+ * ppoll() is preferred where available due to its typically higher ceiling
+ * on the number of usable sockets.  We do not use the more-widely-available
+ * poll(2) because it only offers millisecond timeout resolution, which could
+ * be problematic with high --rate settings.
+ *
+ * Function APIs:
+ *
+ * alloc_socket_set: allocate an empty socket set with room for up to
+ *		"count" sockets.
+ *
+ * free_socket_set: deallocate a socket set.
+ *
+ * clear_socket_set: reset a socket set to empty.
+ *
+ * add_socket_to_set: add socket with indicated FD to slot "idx" in the
+ *		socket set.  Slots must be filled in order, starting with 0.
+ *
+ * wait_on_socket_set: wait for input on any socket in set, or for timeout
+ *		to expire.  timeout is measured in microseconds; 0 means wait forever.
+ *		Returns result code of underlying syscall (>=0 if OK, else see errno).
+ *
+ * socket_has_input: after waiting, call this to see if given socket has
+ *		input.  fd and idx parameters should match some previous call to
+ *		add_socket_to_set.
+ *
+ * Note that wait_on_socket_set destructively modifies the state of the
+ * socket set.  After checking for input, caller must apply clear_socket_set
+ * and add_socket_to_set again before waiting again.
+ */
+
+#ifdef POLL_USING_PPOLL
+
+static socket_set *
+alloc_socket_set(int count)
+{
+	socket_set *sa;
+
+	sa = (socket_set *) pg_malloc0(offsetof(socket_set, pollfds) +
+								   sizeof(struct pollfd) * count);
+	sa->maxfds = count;
+	sa->curfds = 0;
+	return sa;
+}
+
+static void
+free_socket_set(socket_set *sa)
+{
+	pg_free(sa);
+}
+
+static void
+clear_socket_set(socket_set *sa)
+{
+	sa->curfds = 0;
+}
+
+static void
+add_socket_to_set(socket_set *sa, int fd, int idx)
+{
+	Assert(idx < sa->maxfds && idx == sa->curfds);
+	sa->pollfds[idx].fd = fd;
+	sa->pollfds[idx].events = POLLIN;
+	sa->pollfds[idx].revents = 0;
+	sa->curfds++;
+}
+
+static int
+wait_on_socket_set(socket_set *sa, int64 usecs)
+{
+	if (usecs > 0)
+	{
+		struct timespec timeout;
+
+		timeout.tv_sec = usecs / 1000000;
+		timeout.tv_nsec = (usecs % 1000000) * 1000;
+		return ppoll(sa->pollfds, sa->curfds, &timeout, NULL);
+	}
+	else
+	{
+		return ppoll(sa->pollfds, sa->curfds, NULL, NULL);
+	}
+}
+
+static bool
+socket_has_input(socket_set *sa, int fd, int idx)
+{
+	/*
+	 * In some cases, threadRun will apply clear_socket_set and then try to
+	 * apply socket_has_input anyway with arguments that it used before that,
+	 * or might've used before that except that it exited its setup loop
+	 * early.  Hence, if the socket set is empty, silently return false
+	 * regardless of the parameters.  If it's not empty, we can Assert that
+	 * the parameters match a previous call.
+	 */
+	if (sa->curfds == 0)
+		return false;
+
+	Assert(idx < sa->curfds && sa->pollfds[idx].fd == fd);
+	return (sa->pollfds[idx].revents & POLLIN) != 0;
+}
+
+#endif							/* POLL_USING_PPOLL */
+
+#ifdef POLL_USING_SELECT
+
+static socket_set *
+alloc_socket_set(int count)
+{
+	return (socket_set *) pg_malloc0(sizeof(socket_set));
+}
+
+static void
+free_socket_set(socket_set *sa)
+{
+	pg_free(sa);
+}
+
+static void
+clear_socket_set(socket_set *sa)
+{
+	FD_ZERO(&sa->fds);
+	sa->maxfd = -1;
+}
+
+static void
+add_socket_to_set(socket_set *sa, int fd, int idx)
+{
+	if (fd < 0 || fd >= FD_SETSIZE)
+	{
+		/*
+		 * Doing a hard exit here is a bit grotty, but it doesn't seem worth
+		 * complicating the API to make it less grotty.
+		 */
+		pg_log_fatal("too many client connections for select()");
+		exit(1);
+	}
+	FD_SET(fd, &sa->fds);
+	if (fd > sa->maxfd)
+		sa->maxfd = fd;
+}
+
+static int
+wait_on_socket_set(socket_set *sa, int64 usecs)
+{
+	if (usecs > 0)
+	{
+		struct timeval timeout;
+
+		timeout.tv_sec = usecs / 1000000;
+		timeout.tv_usec = usecs % 1000000;
+		return select(sa->maxfd + 1, &sa->fds, NULL, NULL, &timeout);
+	}
+	else
+	{
+		return select(sa->maxfd + 1, &sa->fds, NULL, NULL, NULL);
+	}
+}
+
+static bool
+socket_has_input(socket_set *sa, int fd, int idx)
+{
+	return (FD_ISSET(fd, &sa->fds) != 0);
+}
+
+#endif							/* POLL_USING_SELECT */