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-rw-r--r--ext/expert/README.md83
-rw-r--r--ext/expert/expert.c156
-rw-r--r--ext/expert/expert1.test467
-rw-r--r--ext/expert/sqlite3expert.c2048
-rw-r--r--ext/expert/sqlite3expert.h168
-rw-r--r--ext/expert/test_expert.c220
6 files changed, 3142 insertions, 0 deletions
diff --git a/ext/expert/README.md b/ext/expert/README.md
new file mode 100644
index 0000000..28886fd
--- /dev/null
+++ b/ext/expert/README.md
@@ -0,0 +1,83 @@
+## SQLite Expert Extension
+
+This folder contains code for a simple system to propose useful indexes
+given a database and a set of SQL queries. It works as follows:
+
+ 1. The user database schema is copied to a temporary database.
+
+ 1. All SQL queries are prepared against the temporary database.
+ Information regarding the WHERE and ORDER BY clauses, and other query
+ features that affect index selection are recorded.
+
+ 1. The information gathered in step 2 is used to create candidate
+ indexes - indexes that the planner might have made use of in the previous
+ step, had they been available.
+
+ 1. A subset of the data in the user database is used to generate statistics
+ for all existing indexes and the candidate indexes generated in step 3
+ above.
+
+ 1. The SQL queries are prepared a second time. If the planner uses any
+ of the indexes created in step 3, they are recommended to the user.
+
+# C API
+
+The SQLite expert C API is defined in sqlite3expert.h. Most uses will proceed
+as follows:
+
+ 1. An sqlite3expert object is created by calling **sqlite3\_expert\_new()**.
+ A database handle opened by the user is passed as an argument.
+
+ 1. The sqlite3expert object is configured with one or more SQL statements
+ by making one or more calls to **sqlite3\_expert\_sql()**. Each call may
+ specify a single SQL statement, or multiple statements separated by
+ semi-colons.
+
+ 1. Optionally, the **sqlite3\_expert\_config()** API may be used to
+ configure the size of the data subset used to generate index statistics.
+ Using a smaller subset of the data can speed up the analysis.
+
+ 1. **sqlite3\_expert\_analyze()** is called to run the analysis.
+
+ 1. One or more calls are made to **sqlite3\_expert\_report()** to extract
+ components of the results of the analysis.
+
+ 1. **sqlite3\_expert\_destroy()** is called to free all resources.
+
+Refer to comments in sqlite3expert.h for further details.
+
+# sqlite3_expert application
+
+The file "expert.c" contains the code for a command line application that
+uses the API described above. It can be compiled with (for example):
+
+<pre>
+ gcc -O2 sqlite3.c expert.c sqlite3expert.c -o sqlite3_expert
+</pre>
+
+Assuming the database is named "test.db", it can then be run to analyze a
+single query:
+
+<pre>
+ ./sqlite3_expert -sql &lt;sql-query&gt; test.db
+</pre>
+
+Or an entire text file worth of queries with:
+
+<pre>
+ ./sqlite3_expert -file &lt;text-file&gt; test.db
+</pre>
+
+By default, sqlite3\_expert generates index statistics using all the data in
+the user database. For a large database, this may be prohibitively time
+consuming. The "-sample" option may be used to configure sqlite3\_expert to
+generate statistics based on an integer percentage of the user database as
+follows:
+
+<pre>
+ # Generate statistics based on 25% of the user database rows:
+ ./sqlite3_expert -sample 25 -sql &lt;sql-query&gt; test.db
+
+ # Do not generate any statistics at all:
+ ./sqlite3_expert -sample 0 -sql &lt;sql-query&gt; test.db
+</pre>
diff --git a/ext/expert/expert.c b/ext/expert/expert.c
new file mode 100644
index 0000000..051480f
--- /dev/null
+++ b/ext/expert/expert.c
@@ -0,0 +1,156 @@
+/*
+** 2017 April 07
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+*/
+
+
+#include <sqlite3.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "sqlite3expert.h"
+
+
+static void option_requires_argument(const char *zOpt){
+ fprintf(stderr, "Option requires an argument: %s\n", zOpt);
+ exit(-3);
+}
+
+static int option_integer_arg(const char *zVal){
+ return atoi(zVal);
+}
+
+static void usage(char **argv){
+ fprintf(stderr, "\n");
+ fprintf(stderr, "Usage %s ?OPTIONS? DATABASE\n", argv[0]);
+ fprintf(stderr, "\n");
+ fprintf(stderr, "Options are:\n");
+ fprintf(stderr, " -sql SQL (analyze SQL statements passed as argument)\n");
+ fprintf(stderr, " -file FILE (read SQL statements from file FILE)\n");
+ fprintf(stderr, " -verbose LEVEL (integer verbosity level. default 1)\n");
+ fprintf(stderr, " -sample PERCENT (percent of db to sample. default 100)\n");
+ exit(-1);
+}
+
+static int readSqlFromFile(sqlite3expert *p, const char *zFile, char **pzErr){
+ FILE *in = fopen(zFile, "rb");
+ long nIn;
+ size_t nRead;
+ char *pBuf;
+ int rc;
+ if( in==0 ){
+ *pzErr = sqlite3_mprintf("failed to open file %s\n", zFile);
+ return SQLITE_ERROR;
+ }
+ fseek(in, 0, SEEK_END);
+ nIn = ftell(in);
+ rewind(in);
+ pBuf = sqlite3_malloc64( nIn+1 );
+ nRead = fread(pBuf, nIn, 1, in);
+ fclose(in);
+ if( nRead!=1 ){
+ sqlite3_free(pBuf);
+ *pzErr = sqlite3_mprintf("failed to read file %s\n", zFile);
+ return SQLITE_ERROR;
+ }
+ pBuf[nIn] = 0;
+ rc = sqlite3_expert_sql(p, pBuf, pzErr);
+ sqlite3_free(pBuf);
+ return rc;
+}
+
+int main(int argc, char **argv){
+ const char *zDb;
+ int rc = 0;
+ char *zErr = 0;
+ int i;
+ int iVerbose = 1; /* -verbose option */
+
+ sqlite3 *db = 0;
+ sqlite3expert *p = 0;
+
+ if( argc<2 ) usage(argv);
+ zDb = argv[argc-1];
+ if( zDb[0]=='-' ) usage(argv);
+ rc = sqlite3_open(zDb, &db);
+ if( rc!=SQLITE_OK ){
+ fprintf(stderr, "Cannot open db file: %s - %s\n", zDb, sqlite3_errmsg(db));
+ exit(-2);
+ }
+
+ p = sqlite3_expert_new(db, &zErr);
+ if( p==0 ){
+ fprintf(stderr, "Cannot run analysis: %s\n", zErr);
+ rc = 1;
+ }else{
+ for(i=1; i<(argc-1); i++){
+ char *zArg = argv[i];
+ int nArg;
+ if( zArg[0]=='-' && zArg[1]=='-' && zArg[2]!=0 ) zArg++;
+ nArg = (int)strlen(zArg);
+ if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-file", nArg) ){
+ if( ++i==(argc-1) ) option_requires_argument("-file");
+ rc = readSqlFromFile(p, argv[i], &zErr);
+ }
+
+ else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sql", nArg) ){
+ if( ++i==(argc-1) ) option_requires_argument("-sql");
+ rc = sqlite3_expert_sql(p, argv[i], &zErr);
+ }
+
+ else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sample", nArg) ){
+ int iSample;
+ if( ++i==(argc-1) ) option_requires_argument("-sample");
+ iSample = option_integer_arg(argv[i]);
+ sqlite3_expert_config(p, EXPERT_CONFIG_SAMPLE, iSample);
+ }
+
+ else if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-verbose", nArg) ){
+ if( ++i==(argc-1) ) option_requires_argument("-verbose");
+ iVerbose = option_integer_arg(argv[i]);
+ }
+
+ else{
+ usage(argv);
+ }
+ }
+ }
+
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_expert_analyze(p, &zErr);
+ }
+
+ if( rc==SQLITE_OK ){
+ int nQuery = sqlite3_expert_count(p);
+ if( iVerbose>0 ){
+ const char *zCand = sqlite3_expert_report(p,0,EXPERT_REPORT_CANDIDATES);
+ fprintf(stdout, "-- Candidates -------------------------------\n");
+ fprintf(stdout, "%s\n", zCand);
+ }
+ for(i=0; i<nQuery; i++){
+ const char *zSql = sqlite3_expert_report(p, i, EXPERT_REPORT_SQL);
+ const char *zIdx = sqlite3_expert_report(p, i, EXPERT_REPORT_INDEXES);
+ const char *zEQP = sqlite3_expert_report(p, i, EXPERT_REPORT_PLAN);
+ if( zIdx==0 ) zIdx = "(no new indexes)\n";
+ if( iVerbose>0 ){
+ fprintf(stdout, "-- Query %d ----------------------------------\n",i+1);
+ fprintf(stdout, "%s\n\n", zSql);
+ }
+ fprintf(stdout, "%s\n%s\n", zIdx, zEQP);
+ }
+ }else{
+ fprintf(stderr, "Error: %s\n", zErr ? zErr : "?");
+ }
+
+ sqlite3_expert_destroy(p);
+ sqlite3_free(zErr);
+ return rc;
+}
diff --git a/ext/expert/expert1.test b/ext/expert/expert1.test
new file mode 100644
index 0000000..dee4eb9
--- /dev/null
+++ b/ext/expert/expert1.test
@@ -0,0 +1,467 @@
+# 2009 Nov 11
+#
+# The author disclaims copyright to this source code. In place of
+# a legal notice, here is a blessing:
+#
+# May you do good and not evil.
+# May you find forgiveness for yourself and forgive others.
+# May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# The focus of this file is testing the CLI shell tool. Specifically,
+# the ".recommend" command.
+#
+#
+
+# Test plan:
+#
+#
+if {![info exists testdir]} {
+ set testdir [file join [file dirname [info script]] .. .. test]
+}
+source $testdir/tester.tcl
+set testprefix expert1
+
+if {[info commands sqlite3_expert_new]==""} {
+ finish_test
+ return
+}
+
+
+set CLI [test_binary_name sqlite3]
+set CMD [test_binary_name sqlite3_expert]
+
+proc squish {txt} {
+ regsub -all {[[:space:]]+} $txt { }
+}
+
+proc do_setup_rec_test {tn setup sql res} {
+ reset_db
+ if {[info exists ::set_main_db_name]} {
+ dbconfig_maindbname_icecube db
+ }
+ db eval $setup
+ uplevel [list do_rec_test $tn $sql $res]
+}
+
+foreach {tn setup} {
+ 1 {
+ if {![file executable $CMD]} { continue }
+
+ proc do_rec_test {tn sql res} {
+ set res [squish [string trim $res]]
+ set tst [subst -nocommands {
+ squish [string trim [exec $::CMD -verbose 0 -sql {$sql;} test.db]]
+ }]
+ uplevel [list do_test $tn $tst $res]
+ }
+ }
+ 2 {
+ if {[info commands sqlite3_expert_new]==""} { continue }
+
+ proc do_rec_test {tn sql res} {
+ set expert [sqlite3_expert_new db]
+ $expert sql $sql
+ $expert analyze
+
+ set result [list]
+ for {set i 0} {$i < [$expert count]} {incr i} {
+ set idx [string trim [$expert report $i indexes]]
+ if {$idx==""} {set idx "(no new indexes)"}
+ lappend result $idx
+ lappend result [string trim [$expert report $i plan]]
+ }
+
+ $expert destroy
+
+ set tst [subst -nocommands {set {} [squish [join {$result}]]}]
+ uplevel [list do_test $tn $tst [string trim [squish $res]]]
+ }
+ }
+ 3 {
+ if {[info commands sqlite3_expert_new]==""} { continue }
+ set ::set_main_db_name 1
+ }
+ 4 {
+ if {![file executable $CLI]} { continue }
+
+ proc do_rec_test {tn sql res} {
+ set res [squish [string trim $res]]
+ set tst [subst -nocommands {
+ squish [string trim [exec $::CLI test.db ".expert" {$sql;}]]
+ }]
+ uplevel [list do_test $tn $tst $res]
+ }
+ }
+} {
+
+ eval $setup
+
+
+do_setup_rec_test $tn.1 { CREATE TABLE t1(a, b, c) } {
+ SELECT * FROM t1
+} {
+ (no new indexes)
+ SCAN t1
+}
+
+do_setup_rec_test $tn.2 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT * FROM t1 WHERE b>?;
+} {
+ CREATE INDEX t1_idx_00000062 ON t1(b);
+ SEARCH t1 USING INDEX t1_idx_00000062 (b>?)
+}
+
+do_setup_rec_test $tn.3 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT * FROM t1 WHERE b COLLATE nocase BETWEEN ? AND ?
+} {
+ CREATE INDEX t1_idx_3e094c27 ON t1(b COLLATE NOCASE);
+ SEARCH t1 USING INDEX t1_idx_3e094c27 (b>? AND b<?)
+}
+
+do_setup_rec_test $tn.4 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT a FROM t1 ORDER BY b;
+} {
+ CREATE INDEX t1_idx_00000062 ON t1(b);
+ SCAN t1 USING INDEX t1_idx_00000062
+}
+
+do_setup_rec_test $tn.5 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT a FROM t1 WHERE a=? ORDER BY b;
+} {
+ CREATE INDEX t1_idx_000123a7 ON t1(a, b);
+ SEARCH t1 USING COVERING INDEX t1_idx_000123a7 (a=?)
+}
+
+if 0 {
+do_setup_rec_test $tn.6 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT min(a) FROM t1
+} {
+ CREATE INDEX t1_idx_00000061 ON t1(a);
+ SEARCH t1 USING COVERING INDEX t1_idx_00000061
+}
+}
+
+do_setup_rec_test $tn.7 {
+ CREATE TABLE t1(a, b, c);
+} {
+ SELECT * FROM t1 ORDER BY a, b, c;
+} {
+ CREATE INDEX t1_idx_033e95fe ON t1(a, b, c);
+ SCAN t1 USING COVERING INDEX t1_idx_033e95fe
+}
+
+#do_setup_rec_test $tn.1.8 {
+# CREATE TABLE t1(a, b, c);
+#} {
+# SELECT * FROM t1 ORDER BY a ASC, b COLLATE nocase DESC, c ASC;
+#} {
+# CREATE INDEX t1_idx_5be6e222 ON t1(a, b COLLATE NOCASE DESC, c);
+# 0|0|0|SCAN t1 USING COVERING INDEX t1_idx_5be6e222
+#}
+
+do_setup_rec_test $tn.8.1 {
+ CREATE TABLE t1(a COLLATE NOCase, b, c);
+} {
+ SELECT * FROM t1 WHERE a=?
+} {
+ CREATE INDEX t1_idx_00000061 ON t1(a);
+ SEARCH t1 USING INDEX t1_idx_00000061 (a=?)
+}
+do_setup_rec_test $tn.8.2 {
+ CREATE TABLE t1(a, b COLLATE nocase, c);
+} {
+ SELECT * FROM t1 ORDER BY a ASC, b DESC, c ASC;
+} {
+ CREATE INDEX t1_idx_5cb97285 ON t1(a, b DESC, c);
+ SCAN t1 USING COVERING INDEX t1_idx_5cb97285
+}
+
+
+# Tables with names that require quotes.
+#
+do_setup_rec_test $tn.9.1 {
+ CREATE TABLE "t t"(a, b, c);
+} {
+ SELECT * FROM "t t" WHERE a=?
+} {
+ CREATE INDEX "t t_idx_00000061" ON "t t"(a);
+ SEARCH t t USING INDEX t t_idx_00000061 (a=?)
+}
+
+do_setup_rec_test $tn.9.2 {
+ CREATE TABLE "t t"(a, b, c);
+} {
+ SELECT * FROM "t t" WHERE b BETWEEN ? AND ?
+} {
+ CREATE INDEX "t t_idx_00000062" ON "t t"(b);
+ SEARCH t t USING INDEX t t_idx_00000062 (b>? AND b<?)
+}
+
+# Columns with names that require quotes.
+#
+do_setup_rec_test $tn.10.1 {
+ CREATE TABLE t3(a, "b b", c);
+} {
+ SELECT * FROM t3 WHERE "b b" = ?
+} {
+ CREATE INDEX t3_idx_00050c52 ON t3('b b');
+ SEARCH t3 USING INDEX t3_idx_00050c52 (b b=?)
+}
+
+do_setup_rec_test $tn.10.2 {
+ CREATE TABLE t3(a, "b b", c);
+} {
+ SELECT * FROM t3 ORDER BY "b b"
+} {
+ CREATE INDEX t3_idx_00050c52 ON t3('b b');
+ SCAN t3 USING INDEX t3_idx_00050c52
+}
+
+# Transitive constraints
+#
+do_setup_rec_test $tn.11.1 {
+ CREATE TABLE t5(a, b);
+ CREATE TABLE t6(c, d);
+} {
+ SELECT * FROM t5, t6 WHERE a=? AND b=c AND c=?
+} {
+ CREATE INDEX t5_idx_000123a7 ON t5(a, b);
+ CREATE INDEX t6_idx_00000063 ON t6(c);
+ SEARCH t6 USING INDEX t6_idx_00000063 (c=?)
+ SEARCH t5 USING COVERING INDEX t5_idx_000123a7 (a=? AND b=?)
+}
+
+# OR terms.
+#
+do_setup_rec_test $tn.12.1 {
+ CREATE TABLE t7(a, b);
+} {
+ SELECT * FROM t7 WHERE a=? OR b=?
+} {
+ CREATE INDEX t7_idx_00000062 ON t7(b);
+ CREATE INDEX t7_idx_00000061 ON t7(a);
+ MULTI-INDEX OR
+ INDEX 1
+ SEARCH t7 USING INDEX t7_idx_00000061 (a=?)
+ INDEX 2
+ SEARCH t7 USING INDEX t7_idx_00000062 (b=?)
+}
+
+# rowid terms.
+#
+do_setup_rec_test $tn.13.1 {
+ CREATE TABLE t8(a, b);
+} {
+ SELECT * FROM t8 WHERE rowid=?
+} {
+ (no new indexes)
+ SEARCH t8 USING INTEGER PRIMARY KEY (rowid=?)
+}
+do_setup_rec_test $tn.13.2 {
+ CREATE TABLE t8(a, b);
+} {
+ SELECT * FROM t8 ORDER BY rowid
+} {
+ (no new indexes)
+ SCAN t8
+}
+do_setup_rec_test $tn.13.3 {
+ CREATE TABLE t8(a, b);
+} {
+ SELECT * FROM t8 WHERE a=? ORDER BY rowid
+} {
+ CREATE INDEX t8_idx_00000061 ON t8(a);
+ SEARCH t8 USING INDEX t8_idx_00000061 (a=?)
+}
+
+# Triggers
+#
+do_setup_rec_test $tn.14 {
+ CREATE TABLE t9(a, b, c);
+ CREATE TABLE t10(a, b, c);
+ CREATE TRIGGER t9t AFTER INSERT ON t9 BEGIN
+ UPDATE t10 SET a=new.a WHERE b = new.b;
+ END;
+} {
+ INSERT INTO t9 VALUES(?, ?, ?);
+} {
+ CREATE INDEX t10_idx_00000062 ON t10(b);
+ SEARCH t10 USING INDEX t10_idx_00000062 (b=?)
+}
+
+do_setup_rec_test $tn.15 {
+ CREATE TABLE t1(a, b);
+ CREATE TABLE t2(c, d);
+
+ WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
+ INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;
+
+ WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
+ INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
+} {
+ SELECT * FROM t2, t1 WHERE b=? AND d=? AND t2.rowid=t1.rowid
+} {
+ CREATE INDEX t2_idx_00000064 ON t2(d);
+ SEARCH t2 USING INDEX t2_idx_00000064 (d=?)
+ SEARCH t1 USING INTEGER PRIMARY KEY (rowid=?)
+}
+
+do_setup_rec_test $tn.16 {
+ CREATE TABLE t1(a, b);
+} {
+ SELECT * FROM t1 WHERE b IS NOT NULL;
+} {
+ (no new indexes)
+ SCAN t1
+}
+
+do_setup_rec_test $tn.17.1 {
+ CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+ SELECT * FROM example WHERE a=?
+} {
+ (no new indexes)
+ SEARCH example USING INDEX sqlite_autoindex_example_1 (A=?)
+}
+do_setup_rec_test $tn.17.2 {
+ CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+ SELECT * FROM example WHERE b=?
+} {
+ CREATE INDEX example_idx_00000042 ON example(B);
+ SEARCH example USING INDEX example_idx_00000042 (B=?)
+}
+do_setup_rec_test $tn.17.3 {
+ CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+ SELECT * FROM example WHERE a=? AND b=?
+} {
+ (no new indexes)
+ SEARCH example USING INDEX sqlite_autoindex_example_1 (A=? AND B=?)
+}
+do_setup_rec_test $tn.17.4 {
+ CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+ SELECT * FROM example WHERE a=? AND b>?
+} {
+ (no new indexes)
+ SEARCH example USING INDEX sqlite_autoindex_example_1 (A=? AND B>?)
+}
+do_setup_rec_test $tn.17.5 {
+ CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+ SELECT * FROM example WHERE a>? AND b=?
+} {
+ CREATE INDEX example_idx_0000cb3f ON example(B, A);
+ SEARCH example USING INDEX example_idx_0000cb3f (B=? AND A>?)
+}
+
+do_setup_rec_test $tn.18.0 {
+ CREATE TABLE SomeObject (
+ a INTEGER PRIMARY KEY,
+ x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
+ );
+} {
+ SELECT x FROM SomeObject;
+} {
+ (no new indexes)
+ SCAN SomeObject
+}
+do_setup_rec_test $tn.18.1 {
+ CREATE TABLE SomeObject (
+ a INTEGER PRIMARY KEY,
+ x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
+ );
+} {
+ SELECT * FROM SomeObject WHERE x=?;
+} {
+ CREATE INDEX SomeObject_idx_00000078 ON SomeObject(x);
+ SEARCH SomeObject USING COVERING INDEX SomeObject_idx_00000078 (x=?)
+}
+
+
+do_setup_rec_test $tn.19.0 {
+ CREATE TABLE t1("index");
+} {
+ SELECT * FROM t1 ORDER BY "index";
+} {
+ CREATE INDEX t1_idx_01a7214e ON t1('index');
+ SCAN t1 USING COVERING INDEX t1_idx_01a7214e
+}
+
+}
+
+proc do_candidates_test {tn sql res} {
+ set res [squish [string trim $res]]
+
+ set expert [sqlite3_expert_new db]
+ $expert sql $sql
+ $expert analyze
+
+ set candidates [squish [string trim [$expert report 0 candidates]]]
+ $expert destroy
+
+ uplevel [list do_test $tn [list set {} $candidates] $res]
+}
+
+
+reset_db
+do_execsql_test 5.0 {
+ CREATE TABLE t1(a, b);
+ CREATE TABLE t2(c, d);
+
+ WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
+ INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;
+
+ WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
+ INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
+}
+do_candidates_test 5.1 {
+ SELECT * FROM t1,t2 WHERE (b=? OR a=?) AND (c=? OR d=?)
+} {
+ CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20
+ CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50
+ CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20
+ CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
+}
+
+do_candidates_test 5.2 {
+ SELECT * FROM t1,t2 WHERE a=? AND b=? AND c=? AND d=?
+} {
+ CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 17
+ CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
+}
+
+do_execsql_test 5.3 {
+ CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50
+ CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20
+ CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 16
+
+ CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20
+ CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
+ CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
+
+ ANALYZE;
+ SELECT * FROM sqlite_stat1 ORDER BY 1, 2;
+} {
+ t1 t1_idx_00000061 {100 50}
+ t1 t1_idx_00000062 {100 20}
+ t1 t1_idx_000123a7 {100 50 17}
+ t2 t2_idx_00000063 {100 20}
+ t2 t2_idx_00000064 {100 5}
+ t2 t2_idx_0001295b {100 20 5}
+}
+
+finish_test
diff --git a/ext/expert/sqlite3expert.c b/ext/expert/sqlite3expert.c
new file mode 100644
index 0000000..c01feff
--- /dev/null
+++ b/ext/expert/sqlite3expert.c
@@ -0,0 +1,2048 @@
+/*
+** 2017 April 09
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+*/
+#include "sqlite3expert.h"
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#if !defined(SQLITE_AMALGAMATION)
+#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
+# define SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS 1
+#endif
+#if defined(SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS)
+# define ALWAYS(X) (1)
+# define NEVER(X) (0)
+#elif !defined(NDEBUG)
+# define ALWAYS(X) ((X)?1:(assert(0),0))
+# define NEVER(X) ((X)?(assert(0),1):0)
+#else
+# define ALWAYS(X) (X)
+# define NEVER(X) (X)
+#endif
+#endif /* !defined(SQLITE_AMALGAMATION) */
+
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+typedef sqlite3_int64 i64;
+typedef sqlite3_uint64 u64;
+
+typedef struct IdxColumn IdxColumn;
+typedef struct IdxConstraint IdxConstraint;
+typedef struct IdxScan IdxScan;
+typedef struct IdxStatement IdxStatement;
+typedef struct IdxTable IdxTable;
+typedef struct IdxWrite IdxWrite;
+
+#define STRLEN (int)strlen
+
+/*
+** A temp table name that we assume no user database will actually use.
+** If this assumption proves incorrect triggers on the table with the
+** conflicting name will be ignored.
+*/
+#define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776"
+
+/*
+** A single constraint. Equivalent to either "col = ?" or "col < ?" (or
+** any other type of single-ended range constraint on a column).
+**
+** pLink:
+** Used to temporarily link IdxConstraint objects into lists while
+** creating candidate indexes.
+*/
+struct IdxConstraint {
+ char *zColl; /* Collation sequence */
+ int bRange; /* True for range, false for eq */
+ int iCol; /* Constrained table column */
+ int bFlag; /* Used by idxFindCompatible() */
+ int bDesc; /* True if ORDER BY <expr> DESC */
+ IdxConstraint *pNext; /* Next constraint in pEq or pRange list */
+ IdxConstraint *pLink; /* See above */
+};
+
+/*
+** A single scan of a single table.
+*/
+struct IdxScan {
+ IdxTable *pTab; /* Associated table object */
+ int iDb; /* Database containing table zTable */
+ i64 covering; /* Mask of columns required for cov. index */
+ IdxConstraint *pOrder; /* ORDER BY columns */
+ IdxConstraint *pEq; /* List of == constraints */
+ IdxConstraint *pRange; /* List of < constraints */
+ IdxScan *pNextScan; /* Next IdxScan object for same analysis */
+};
+
+/*
+** Information regarding a single database table. Extracted from
+** "PRAGMA table_info" by function idxGetTableInfo().
+*/
+struct IdxColumn {
+ char *zName;
+ char *zColl;
+ int iPk;
+};
+struct IdxTable {
+ int nCol;
+ char *zName; /* Table name */
+ IdxColumn *aCol;
+ IdxTable *pNext; /* Next table in linked list of all tables */
+};
+
+/*
+** An object of the following type is created for each unique table/write-op
+** seen. The objects are stored in a singly-linked list beginning at
+** sqlite3expert.pWrite.
+*/
+struct IdxWrite {
+ IdxTable *pTab;
+ int eOp; /* SQLITE_UPDATE, DELETE or INSERT */
+ IdxWrite *pNext;
+};
+
+/*
+** Each statement being analyzed is represented by an instance of this
+** structure.
+*/
+struct IdxStatement {
+ int iId; /* Statement number */
+ char *zSql; /* SQL statement */
+ char *zIdx; /* Indexes */
+ char *zEQP; /* Plan */
+ IdxStatement *pNext;
+};
+
+
+/*
+** A hash table for storing strings. With space for a payload string
+** with each entry. Methods are:
+**
+** idxHashInit()
+** idxHashClear()
+** idxHashAdd()
+** idxHashSearch()
+*/
+#define IDX_HASH_SIZE 1023
+typedef struct IdxHashEntry IdxHashEntry;
+typedef struct IdxHash IdxHash;
+struct IdxHashEntry {
+ char *zKey; /* nul-terminated key */
+ char *zVal; /* nul-terminated value string */
+ char *zVal2; /* nul-terminated value string 2 */
+ IdxHashEntry *pHashNext; /* Next entry in same hash bucket */
+ IdxHashEntry *pNext; /* Next entry in hash */
+};
+struct IdxHash {
+ IdxHashEntry *pFirst;
+ IdxHashEntry *aHash[IDX_HASH_SIZE];
+};
+
+/*
+** sqlite3expert object.
+*/
+struct sqlite3expert {
+ int iSample; /* Percentage of tables to sample for stat1 */
+ sqlite3 *db; /* User database */
+ sqlite3 *dbm; /* In-memory db for this analysis */
+ sqlite3 *dbv; /* Vtab schema for this analysis */
+ IdxTable *pTable; /* List of all IdxTable objects */
+ IdxScan *pScan; /* List of scan objects */
+ IdxWrite *pWrite; /* List of write objects */
+ IdxStatement *pStatement; /* List of IdxStatement objects */
+ int bRun; /* True once analysis has run */
+ char **pzErrmsg;
+ int rc; /* Error code from whereinfo hook */
+ IdxHash hIdx; /* Hash containing all candidate indexes */
+ char *zCandidates; /* For EXPERT_REPORT_CANDIDATES */
+};
+
+
+/*
+** Allocate and return nByte bytes of zeroed memory using sqlite3_malloc().
+** If the allocation fails, set *pRc to SQLITE_NOMEM and return NULL.
+*/
+static void *idxMalloc(int *pRc, int nByte){
+ void *pRet;
+ assert( *pRc==SQLITE_OK );
+ assert( nByte>0 );
+ pRet = sqlite3_malloc(nByte);
+ if( pRet ){
+ memset(pRet, 0, nByte);
+ }else{
+ *pRc = SQLITE_NOMEM;
+ }
+ return pRet;
+}
+
+/*
+** Initialize an IdxHash hash table.
+*/
+static void idxHashInit(IdxHash *pHash){
+ memset(pHash, 0, sizeof(IdxHash));
+}
+
+/*
+** Reset an IdxHash hash table.
+*/
+static void idxHashClear(IdxHash *pHash){
+ int i;
+ for(i=0; i<IDX_HASH_SIZE; i++){
+ IdxHashEntry *pEntry;
+ IdxHashEntry *pNext;
+ for(pEntry=pHash->aHash[i]; pEntry; pEntry=pNext){
+ pNext = pEntry->pHashNext;
+ sqlite3_free(pEntry->zVal2);
+ sqlite3_free(pEntry);
+ }
+ }
+ memset(pHash, 0, sizeof(IdxHash));
+}
+
+/*
+** Return the index of the hash bucket that the string specified by the
+** arguments to this function belongs.
+*/
+static int idxHashString(const char *z, int n){
+ unsigned int ret = 0;
+ int i;
+ for(i=0; i<n; i++){
+ ret += (ret<<3) + (unsigned char)(z[i]);
+ }
+ return (int)(ret % IDX_HASH_SIZE);
+}
+
+/*
+** If zKey is already present in the hash table, return non-zero and do
+** nothing. Otherwise, add an entry with key zKey and payload string zVal to
+** the hash table passed as the second argument.
+*/
+static int idxHashAdd(
+ int *pRc,
+ IdxHash *pHash,
+ const char *zKey,
+ const char *zVal
+){
+ int nKey = STRLEN(zKey);
+ int iHash = idxHashString(zKey, nKey);
+ int nVal = (zVal ? STRLEN(zVal) : 0);
+ IdxHashEntry *pEntry;
+ assert( iHash>=0 );
+ for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
+ if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
+ return 1;
+ }
+ }
+ pEntry = idxMalloc(pRc, sizeof(IdxHashEntry) + nKey+1 + nVal+1);
+ if( pEntry ){
+ pEntry->zKey = (char*)&pEntry[1];
+ memcpy(pEntry->zKey, zKey, nKey);
+ if( zVal ){
+ pEntry->zVal = &pEntry->zKey[nKey+1];
+ memcpy(pEntry->zVal, zVal, nVal);
+ }
+ pEntry->pHashNext = pHash->aHash[iHash];
+ pHash->aHash[iHash] = pEntry;
+
+ pEntry->pNext = pHash->pFirst;
+ pHash->pFirst = pEntry;
+ }
+ return 0;
+}
+
+/*
+** If zKey/nKey is present in the hash table, return a pointer to the
+** hash-entry object.
+*/
+static IdxHashEntry *idxHashFind(IdxHash *pHash, const char *zKey, int nKey){
+ int iHash;
+ IdxHashEntry *pEntry;
+ if( nKey<0 ) nKey = STRLEN(zKey);
+ iHash = idxHashString(zKey, nKey);
+ assert( iHash>=0 );
+ for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
+ if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
+ return pEntry;
+ }
+ }
+ return 0;
+}
+
+/*
+** If the hash table contains an entry with a key equal to the string
+** passed as the final two arguments to this function, return a pointer
+** to the payload string. Otherwise, if zKey/nKey is not present in the
+** hash table, return NULL.
+*/
+static const char *idxHashSearch(IdxHash *pHash, const char *zKey, int nKey){
+ IdxHashEntry *pEntry = idxHashFind(pHash, zKey, nKey);
+ if( pEntry ) return pEntry->zVal;
+ return 0;
+}
+
+/*
+** Allocate and return a new IdxConstraint object. Set the IdxConstraint.zColl
+** variable to point to a copy of nul-terminated string zColl.
+*/
+static IdxConstraint *idxNewConstraint(int *pRc, const char *zColl){
+ IdxConstraint *pNew;
+ int nColl = STRLEN(zColl);
+
+ assert( *pRc==SQLITE_OK );
+ pNew = (IdxConstraint*)idxMalloc(pRc, sizeof(IdxConstraint) * nColl + 1);
+ if( pNew ){
+ pNew->zColl = (char*)&pNew[1];
+ memcpy(pNew->zColl, zColl, nColl+1);
+ }
+ return pNew;
+}
+
+/*
+** An error associated with database handle db has just occurred. Pass
+** the error message to callback function xOut.
+*/
+static void idxDatabaseError(
+ sqlite3 *db, /* Database handle */
+ char **pzErrmsg /* Write error here */
+){
+ *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
+}
+
+/*
+** Prepare an SQL statement.
+*/
+static int idxPrepareStmt(
+ sqlite3 *db, /* Database handle to compile against */
+ sqlite3_stmt **ppStmt, /* OUT: Compiled SQL statement */
+ char **pzErrmsg, /* OUT: sqlite3_malloc()ed error message */
+ const char *zSql /* SQL statement to compile */
+){
+ int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
+ if( rc!=SQLITE_OK ){
+ *ppStmt = 0;
+ idxDatabaseError(db, pzErrmsg);
+ }
+ return rc;
+}
+
+/*
+** Prepare an SQL statement using the results of a printf() formatting.
+*/
+static int idxPrintfPrepareStmt(
+ sqlite3 *db, /* Database handle to compile against */
+ sqlite3_stmt **ppStmt, /* OUT: Compiled SQL statement */
+ char **pzErrmsg, /* OUT: sqlite3_malloc()ed error message */
+ const char *zFmt, /* printf() format of SQL statement */
+ ... /* Trailing printf() arguments */
+){
+ va_list ap;
+ int rc;
+ char *zSql;
+ va_start(ap, zFmt);
+ zSql = sqlite3_vmprintf(zFmt, ap);
+ if( zSql==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = idxPrepareStmt(db, ppStmt, pzErrmsg, zSql);
+ sqlite3_free(zSql);
+ }
+ va_end(ap);
+ return rc;
+}
+
+
+/*************************************************************************
+** Beginning of virtual table implementation.
+*/
+typedef struct ExpertVtab ExpertVtab;
+struct ExpertVtab {
+ sqlite3_vtab base;
+ IdxTable *pTab;
+ sqlite3expert *pExpert;
+};
+
+typedef struct ExpertCsr ExpertCsr;
+struct ExpertCsr {
+ sqlite3_vtab_cursor base;
+ sqlite3_stmt *pData;
+};
+
+static char *expertDequote(const char *zIn){
+ int n = STRLEN(zIn);
+ char *zRet = sqlite3_malloc(n);
+
+ assert( zIn[0]=='\'' );
+ assert( zIn[n-1]=='\'' );
+
+ if( zRet ){
+ int iOut = 0;
+ int iIn = 0;
+ for(iIn=1; iIn<(n-1); iIn++){
+ if( zIn[iIn]=='\'' ){
+ assert( zIn[iIn+1]=='\'' );
+ iIn++;
+ }
+ zRet[iOut++] = zIn[iIn];
+ }
+ zRet[iOut] = '\0';
+ }
+
+ return zRet;
+}
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the r-tree virtual table.
+**
+** argv[0] -> module name
+** argv[1] -> database name
+** argv[2] -> table name
+** argv[...] -> column names...
+*/
+static int expertConnect(
+ sqlite3 *db,
+ void *pAux,
+ int argc, const char *const*argv,
+ sqlite3_vtab **ppVtab,
+ char **pzErr
+){
+ sqlite3expert *pExpert = (sqlite3expert*)pAux;
+ ExpertVtab *p = 0;
+ int rc;
+
+ if( argc!=4 ){
+ *pzErr = sqlite3_mprintf("internal error!");
+ rc = SQLITE_ERROR;
+ }else{
+ char *zCreateTable = expertDequote(argv[3]);
+ if( zCreateTable ){
+ rc = sqlite3_declare_vtab(db, zCreateTable);
+ if( rc==SQLITE_OK ){
+ p = idxMalloc(&rc, sizeof(ExpertVtab));
+ }
+ if( rc==SQLITE_OK ){
+ p->pExpert = pExpert;
+ p->pTab = pExpert->pTable;
+ assert( sqlite3_stricmp(p->pTab->zName, argv[2])==0 );
+ }
+ sqlite3_free(zCreateTable);
+ }else{
+ rc = SQLITE_NOMEM;
+ }
+ }
+
+ *ppVtab = (sqlite3_vtab*)p;
+ return rc;
+}
+
+static int expertDisconnect(sqlite3_vtab *pVtab){
+ ExpertVtab *p = (ExpertVtab*)pVtab;
+ sqlite3_free(p);
+ return SQLITE_OK;
+}
+
+static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
+ ExpertVtab *p = (ExpertVtab*)pVtab;
+ int rc = SQLITE_OK;
+ int n = 0;
+ IdxScan *pScan;
+ const int opmask =
+ SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
+ SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
+ SQLITE_INDEX_CONSTRAINT_LE;
+
+ pScan = idxMalloc(&rc, sizeof(IdxScan));
+ if( pScan ){
+ int i;
+
+ /* Link the new scan object into the list */
+ pScan->pTab = p->pTab;
+ pScan->pNextScan = p->pExpert->pScan;
+ p->pExpert->pScan = pScan;
+
+ /* Add the constraints to the IdxScan object */
+ for(i=0; i<pIdxInfo->nConstraint; i++){
+ struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
+ if( pCons->usable
+ && pCons->iColumn>=0
+ && p->pTab->aCol[pCons->iColumn].iPk==0
+ && (pCons->op & opmask)
+ ){
+ IdxConstraint *pNew;
+ const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
+ pNew = idxNewConstraint(&rc, zColl);
+ if( pNew ){
+ pNew->iCol = pCons->iColumn;
+ if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+ pNew->pNext = pScan->pEq;
+ pScan->pEq = pNew;
+ }else{
+ pNew->bRange = 1;
+ pNew->pNext = pScan->pRange;
+ pScan->pRange = pNew;
+ }
+ }
+ n++;
+ pIdxInfo->aConstraintUsage[i].argvIndex = n;
+ }
+ }
+
+ /* Add the ORDER BY to the IdxScan object */
+ for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
+ int iCol = pIdxInfo->aOrderBy[i].iColumn;
+ if( iCol>=0 ){
+ IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
+ if( pNew ){
+ pNew->iCol = iCol;
+ pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
+ pNew->pNext = pScan->pOrder;
+ pNew->pLink = pScan->pOrder;
+ pScan->pOrder = pNew;
+ n++;
+ }
+ }
+ }
+ }
+
+ pIdxInfo->estimatedCost = 1000000.0 / (n+1);
+ return rc;
+}
+
+static int expertUpdate(
+ sqlite3_vtab *pVtab,
+ int nData,
+ sqlite3_value **azData,
+ sqlite_int64 *pRowid
+){
+ (void)pVtab;
+ (void)nData;
+ (void)azData;
+ (void)pRowid;
+ return SQLITE_OK;
+}
+
+/*
+** Virtual table module xOpen method.
+*/
+static int expertOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+ int rc = SQLITE_OK;
+ ExpertCsr *pCsr;
+ (void)pVTab;
+ pCsr = idxMalloc(&rc, sizeof(ExpertCsr));
+ *ppCursor = (sqlite3_vtab_cursor*)pCsr;
+ return rc;
+}
+
+/*
+** Virtual table module xClose method.
+*/
+static int expertClose(sqlite3_vtab_cursor *cur){
+ ExpertCsr *pCsr = (ExpertCsr*)cur;
+ sqlite3_finalize(pCsr->pData);
+ sqlite3_free(pCsr);
+ return SQLITE_OK;
+}
+
+/*
+** Virtual table module xEof method.
+**
+** Return non-zero if the cursor does not currently point to a valid
+** record (i.e if the scan has finished), or zero otherwise.
+*/
+static int expertEof(sqlite3_vtab_cursor *cur){
+ ExpertCsr *pCsr = (ExpertCsr*)cur;
+ return pCsr->pData==0;
+}
+
+/*
+** Virtual table module xNext method.
+*/
+static int expertNext(sqlite3_vtab_cursor *cur){
+ ExpertCsr *pCsr = (ExpertCsr*)cur;
+ int rc = SQLITE_OK;
+
+ assert( pCsr->pData );
+ rc = sqlite3_step(pCsr->pData);
+ if( rc!=SQLITE_ROW ){
+ rc = sqlite3_finalize(pCsr->pData);
+ pCsr->pData = 0;
+ }else{
+ rc = SQLITE_OK;
+ }
+
+ return rc;
+}
+
+/*
+** Virtual table module xRowid method.
+*/
+static int expertRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+ (void)cur;
+ *pRowid = 0;
+ return SQLITE_OK;
+}
+
+/*
+** Virtual table module xColumn method.
+*/
+static int expertColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+ ExpertCsr *pCsr = (ExpertCsr*)cur;
+ sqlite3_value *pVal;
+ pVal = sqlite3_column_value(pCsr->pData, i);
+ if( pVal ){
+ sqlite3_result_value(ctx, pVal);
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Virtual table module xFilter method.
+*/
+static int expertFilter(
+ sqlite3_vtab_cursor *cur,
+ int idxNum, const char *idxStr,
+ int argc, sqlite3_value **argv
+){
+ ExpertCsr *pCsr = (ExpertCsr*)cur;
+ ExpertVtab *pVtab = (ExpertVtab*)(cur->pVtab);
+ sqlite3expert *pExpert = pVtab->pExpert;
+ int rc;
+
+ (void)idxNum;
+ (void)idxStr;
+ (void)argc;
+ (void)argv;
+ rc = sqlite3_finalize(pCsr->pData);
+ pCsr->pData = 0;
+ if( rc==SQLITE_OK ){
+ rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
+ "SELECT * FROM main.%Q WHERE sample()", pVtab->pTab->zName
+ );
+ }
+
+ if( rc==SQLITE_OK ){
+ rc = expertNext(cur);
+ }
+ return rc;
+}
+
+static int idxRegisterVtab(sqlite3expert *p){
+ static sqlite3_module expertModule = {
+ 2, /* iVersion */
+ expertConnect, /* xCreate - create a table */
+ expertConnect, /* xConnect - connect to an existing table */
+ expertBestIndex, /* xBestIndex - Determine search strategy */
+ expertDisconnect, /* xDisconnect - Disconnect from a table */
+ expertDisconnect, /* xDestroy - Drop a table */
+ expertOpen, /* xOpen - open a cursor */
+ expertClose, /* xClose - close a cursor */
+ expertFilter, /* xFilter - configure scan constraints */
+ expertNext, /* xNext - advance a cursor */
+ expertEof, /* xEof */
+ expertColumn, /* xColumn - read data */
+ expertRowid, /* xRowid - read data */
+ expertUpdate, /* xUpdate - write data */
+ 0, /* xBegin - begin transaction */
+ 0, /* xSync - sync transaction */
+ 0, /* xCommit - commit transaction */
+ 0, /* xRollback - rollback transaction */
+ 0, /* xFindFunction - function overloading */
+ 0, /* xRename - rename the table */
+ 0, /* xSavepoint */
+ 0, /* xRelease */
+ 0, /* xRollbackTo */
+ 0, /* xShadowName */
+ };
+
+ return sqlite3_create_module(p->dbv, "expert", &expertModule, (void*)p);
+}
+/*
+** End of virtual table implementation.
+*************************************************************************/
+/*
+** Finalize SQL statement pStmt. If (*pRc) is SQLITE_OK when this function
+** is called, set it to the return value of sqlite3_finalize() before
+** returning. Otherwise, discard the sqlite3_finalize() return value.
+*/
+static void idxFinalize(int *pRc, sqlite3_stmt *pStmt){
+ int rc = sqlite3_finalize(pStmt);
+ if( *pRc==SQLITE_OK ) *pRc = rc;
+}
+
+/*
+** Attempt to allocate an IdxTable structure corresponding to table zTab
+** in the main database of connection db. If successful, set (*ppOut) to
+** point to the new object and return SQLITE_OK. Otherwise, return an
+** SQLite error code and set (*ppOut) to NULL. In this case *pzErrmsg may be
+** set to point to an error string.
+**
+** It is the responsibility of the caller to eventually free either the
+** IdxTable object or error message using sqlite3_free().
+*/
+static int idxGetTableInfo(
+ sqlite3 *db, /* Database connection to read details from */
+ const char *zTab, /* Table name */
+ IdxTable **ppOut, /* OUT: New object (if successful) */
+ char **pzErrmsg /* OUT: Error message (if not) */
+){
+ sqlite3_stmt *p1 = 0;
+ int nCol = 0;
+ int nTab;
+ int nByte;
+ IdxTable *pNew = 0;
+ int rc, rc2;
+ char *pCsr = 0;
+ int nPk = 0;
+
+ *ppOut = 0;
+ if( zTab==0 ) return SQLITE_ERROR;
+ nTab = STRLEN(zTab);
+ nByte = sizeof(IdxTable) + nTab + 1;
+ rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_xinfo=%Q", zTab);
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
+ const char *zCol = (const char*)sqlite3_column_text(p1, 1);
+ const char *zColSeq = 0;
+ if( zCol==0 ){
+ rc = SQLITE_ERROR;
+ break;
+ }
+ nByte += 1 + STRLEN(zCol);
+ rc = sqlite3_table_column_metadata(
+ db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
+ );
+ if( zColSeq==0 ) zColSeq = "binary";
+ nByte += 1 + STRLEN(zColSeq);
+ nCol++;
+ nPk += (sqlite3_column_int(p1, 5)>0);
+ }
+ rc2 = sqlite3_reset(p1);
+ if( rc==SQLITE_OK ) rc = rc2;
+
+ nByte += sizeof(IdxColumn) * nCol;
+ if( rc==SQLITE_OK ){
+ pNew = idxMalloc(&rc, nByte);
+ }
+ if( rc==SQLITE_OK ){
+ pNew->aCol = (IdxColumn*)&pNew[1];
+ pNew->nCol = nCol;
+ pCsr = (char*)&pNew->aCol[nCol];
+ }
+
+ nCol = 0;
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
+ const char *zCol = (const char*)sqlite3_column_text(p1, 1);
+ const char *zColSeq = 0;
+ int nCopy;
+ if( zCol==0 ) continue;
+ nCopy = STRLEN(zCol) + 1;
+ pNew->aCol[nCol].zName = pCsr;
+ pNew->aCol[nCol].iPk = (sqlite3_column_int(p1, 5)==1 && nPk==1);
+ memcpy(pCsr, zCol, nCopy);
+ pCsr += nCopy;
+
+ rc = sqlite3_table_column_metadata(
+ db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
+ );
+ if( rc==SQLITE_OK ){
+ if( zColSeq==0 ) zColSeq = "binary";
+ nCopy = STRLEN(zColSeq) + 1;
+ pNew->aCol[nCol].zColl = pCsr;
+ memcpy(pCsr, zColSeq, nCopy);
+ pCsr += nCopy;
+ }
+
+ nCol++;
+ }
+ idxFinalize(&rc, p1);
+
+ if( rc!=SQLITE_OK ){
+ sqlite3_free(pNew);
+ pNew = 0;
+ }else if( ALWAYS(pNew!=0) ){
+ pNew->zName = pCsr;
+ if( ALWAYS(pNew->zName!=0) ) memcpy(pNew->zName, zTab, nTab+1);
+ }
+
+ *ppOut = pNew;
+ return rc;
+}
+
+/*
+** This function is a no-op if *pRc is set to anything other than
+** SQLITE_OK when it is called.
+**
+** If *pRc is initially set to SQLITE_OK, then the text specified by
+** the printf() style arguments is appended to zIn and the result returned
+** in a buffer allocated by sqlite3_malloc(). sqlite3_free() is called on
+** zIn before returning.
+*/
+static char *idxAppendText(int *pRc, char *zIn, const char *zFmt, ...){
+ va_list ap;
+ char *zAppend = 0;
+ char *zRet = 0;
+ int nIn = zIn ? STRLEN(zIn) : 0;
+ int nAppend = 0;
+ va_start(ap, zFmt);
+ if( *pRc==SQLITE_OK ){
+ zAppend = sqlite3_vmprintf(zFmt, ap);
+ if( zAppend ){
+ nAppend = STRLEN(zAppend);
+ zRet = (char*)sqlite3_malloc(nIn + nAppend + 1);
+ }
+ if( zAppend && zRet ){
+ if( nIn ) memcpy(zRet, zIn, nIn);
+ memcpy(&zRet[nIn], zAppend, nAppend+1);
+ }else{
+ sqlite3_free(zRet);
+ zRet = 0;
+ *pRc = SQLITE_NOMEM;
+ }
+ sqlite3_free(zAppend);
+ sqlite3_free(zIn);
+ }
+ va_end(ap);
+ return zRet;
+}
+
+/*
+** Return true if zId must be quoted in order to use it as an SQL
+** identifier, or false otherwise.
+*/
+static int idxIdentifierRequiresQuotes(const char *zId){
+ int i;
+ int nId = STRLEN(zId);
+
+ if( sqlite3_keyword_check(zId, nId) ) return 1;
+
+ for(i=0; zId[i]; i++){
+ if( !(zId[i]=='_')
+ && !(zId[i]>='0' && zId[i]<='9')
+ && !(zId[i]>='a' && zId[i]<='z')
+ && !(zId[i]>='A' && zId[i]<='Z')
+ ){
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/*
+** This function appends an index column definition suitable for constraint
+** pCons to the string passed as zIn and returns the result.
+*/
+static char *idxAppendColDefn(
+ int *pRc, /* IN/OUT: Error code */
+ char *zIn, /* Column defn accumulated so far */
+ IdxTable *pTab, /* Table index will be created on */
+ IdxConstraint *pCons
+){
+ char *zRet = zIn;
+ IdxColumn *p = &pTab->aCol[pCons->iCol];
+ if( zRet ) zRet = idxAppendText(pRc, zRet, ", ");
+
+ if( idxIdentifierRequiresQuotes(p->zName) ){
+ zRet = idxAppendText(pRc, zRet, "%Q", p->zName);
+ }else{
+ zRet = idxAppendText(pRc, zRet, "%s", p->zName);
+ }
+
+ if( sqlite3_stricmp(p->zColl, pCons->zColl) ){
+ if( idxIdentifierRequiresQuotes(pCons->zColl) ){
+ zRet = idxAppendText(pRc, zRet, " COLLATE %Q", pCons->zColl);
+ }else{
+ zRet = idxAppendText(pRc, zRet, " COLLATE %s", pCons->zColl);
+ }
+ }
+
+ if( pCons->bDesc ){
+ zRet = idxAppendText(pRc, zRet, " DESC");
+ }
+ return zRet;
+}
+
+/*
+** Search database dbm for an index compatible with the one idxCreateFromCons()
+** would create from arguments pScan, pEq and pTail. If no error occurs and
+** such an index is found, return non-zero. Or, if no such index is found,
+** return zero.
+**
+** If an error occurs, set *pRc to an SQLite error code and return zero.
+*/
+static int idxFindCompatible(
+ int *pRc, /* OUT: Error code */
+ sqlite3* dbm, /* Database to search */
+ IdxScan *pScan, /* Scan for table to search for index on */
+ IdxConstraint *pEq, /* List of == constraints */
+ IdxConstraint *pTail /* List of range constraints */
+){
+ const char *zTbl = pScan->pTab->zName;
+ sqlite3_stmt *pIdxList = 0;
+ IdxConstraint *pIter;
+ int nEq = 0; /* Number of elements in pEq */
+ int rc;
+
+ /* Count the elements in list pEq */
+ for(pIter=pEq; pIter; pIter=pIter->pLink) nEq++;
+
+ rc = idxPrintfPrepareStmt(dbm, &pIdxList, 0, "PRAGMA index_list=%Q", zTbl);
+ while( rc==SQLITE_OK && sqlite3_step(pIdxList)==SQLITE_ROW ){
+ int bMatch = 1;
+ IdxConstraint *pT = pTail;
+ sqlite3_stmt *pInfo = 0;
+ const char *zIdx = (const char*)sqlite3_column_text(pIdxList, 1);
+ if( zIdx==0 ) continue;
+
+ /* Zero the IdxConstraint.bFlag values in the pEq list */
+ for(pIter=pEq; pIter; pIter=pIter->pLink) pIter->bFlag = 0;
+
+ rc = idxPrintfPrepareStmt(dbm, &pInfo, 0, "PRAGMA index_xInfo=%Q", zIdx);
+ while( rc==SQLITE_OK && sqlite3_step(pInfo)==SQLITE_ROW ){
+ int iIdx = sqlite3_column_int(pInfo, 0);
+ int iCol = sqlite3_column_int(pInfo, 1);
+ const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);
+
+ if( iIdx<nEq ){
+ for(pIter=pEq; pIter; pIter=pIter->pLink){
+ if( pIter->bFlag ) continue;
+ if( pIter->iCol!=iCol ) continue;
+ if( sqlite3_stricmp(pIter->zColl, zColl) ) continue;
+ pIter->bFlag = 1;
+ break;
+ }
+ if( pIter==0 ){
+ bMatch = 0;
+ break;
+ }
+ }else{
+ if( pT ){
+ if( pT->iCol!=iCol || sqlite3_stricmp(pT->zColl, zColl) ){
+ bMatch = 0;
+ break;
+ }
+ pT = pT->pLink;
+ }
+ }
+ }
+ idxFinalize(&rc, pInfo);
+
+ if( rc==SQLITE_OK && bMatch ){
+ sqlite3_finalize(pIdxList);
+ return 1;
+ }
+ }
+ idxFinalize(&rc, pIdxList);
+
+ *pRc = rc;
+ return 0;
+}
+
+/* Callback for sqlite3_exec() with query with leading count(*) column.
+ * The first argument is expected to be an int*, referent to be incremented
+ * if that leading column is not exactly '0'.
+ */
+static int countNonzeros(void* pCount, int nc,
+ char* azResults[], char* azColumns[]){
+ (void)azColumns; /* Suppress unused parameter warning */
+ if( nc>0 && (azResults[0][0]!='0' || azResults[0][1]!=0) ){
+ *((int *)pCount) += 1;
+ }
+ return 0;
+}
+
+static int idxCreateFromCons(
+ sqlite3expert *p,
+ IdxScan *pScan,
+ IdxConstraint *pEq,
+ IdxConstraint *pTail
+){
+ sqlite3 *dbm = p->dbm;
+ int rc = SQLITE_OK;
+ if( (pEq || pTail) && 0==idxFindCompatible(&rc, dbm, pScan, pEq, pTail) ){
+ IdxTable *pTab = pScan->pTab;
+ char *zCols = 0;
+ char *zIdx = 0;
+ IdxConstraint *pCons;
+ unsigned int h = 0;
+ const char *zFmt;
+
+ for(pCons=pEq; pCons; pCons=pCons->pLink){
+ zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
+ }
+ for(pCons=pTail; pCons; pCons=pCons->pLink){
+ zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
+ }
+
+ if( rc==SQLITE_OK ){
+ /* Hash the list of columns to come up with a name for the index */
+ const char *zTable = pScan->pTab->zName;
+ int quoteTable = idxIdentifierRequiresQuotes(zTable);
+ char *zName = 0; /* Index name */
+ int collisions = 0;
+ do{
+ int i;
+ char *zFind;
+ for(i=0; zCols[i]; i++){
+ h += ((h<<3) + zCols[i]);
+ }
+ sqlite3_free(zName);
+ zName = sqlite3_mprintf("%s_idx_%08x", zTable, h);
+ if( zName==0 ) break;
+ /* Is is unique among table, view and index names? */
+ zFmt = "SELECT count(*) FROM sqlite_schema WHERE name=%Q"
+ " AND type in ('index','table','view')";
+ zFind = sqlite3_mprintf(zFmt, zName);
+ i = 0;
+ rc = sqlite3_exec(dbm, zFind, countNonzeros, &i, 0);
+ assert(rc==SQLITE_OK);
+ sqlite3_free(zFind);
+ if( i==0 ){
+ collisions = 0;
+ break;
+ }
+ ++collisions;
+ }while( collisions<50 && zName!=0 );
+ if( collisions ){
+ /* This return means "Gave up trying to find a unique index name." */
+ rc = SQLITE_BUSY_TIMEOUT;
+ }else if( zName==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ if( quoteTable ){
+ zFmt = "CREATE INDEX \"%w\" ON \"%w\"(%s)";
+ }else{
+ zFmt = "CREATE INDEX %s ON %s(%s)";
+ }
+ zIdx = sqlite3_mprintf(zFmt, zName, zTable, zCols);
+ if( !zIdx ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_exec(dbm, zIdx, 0, 0, p->pzErrmsg);
+ if( rc!=SQLITE_OK ){
+ rc = SQLITE_BUSY_TIMEOUT;
+ }else{
+ idxHashAdd(&rc, &p->hIdx, zName, zIdx);
+ }
+ }
+ sqlite3_free(zName);
+ sqlite3_free(zIdx);
+ }
+ }
+
+ sqlite3_free(zCols);
+ }
+ return rc;
+}
+
+/*
+** Return true if list pList (linked by IdxConstraint.pLink) contains
+** a constraint compatible with *p. Otherwise return false.
+*/
+static int idxFindConstraint(IdxConstraint *pList, IdxConstraint *p){
+ IdxConstraint *pCmp;
+ for(pCmp=pList; pCmp; pCmp=pCmp->pLink){
+ if( p->iCol==pCmp->iCol ) return 1;
+ }
+ return 0;
+}
+
+static int idxCreateFromWhere(
+ sqlite3expert *p,
+ IdxScan *pScan, /* Create indexes for this scan */
+ IdxConstraint *pTail /* range/ORDER BY constraints for inclusion */
+){
+ IdxConstraint *p1 = 0;
+ IdxConstraint *pCon;
+ int rc;
+
+ /* Gather up all the == constraints. */
+ for(pCon=pScan->pEq; pCon; pCon=pCon->pNext){
+ if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
+ pCon->pLink = p1;
+ p1 = pCon;
+ }
+ }
+
+ /* Create an index using the == constraints collected above. And the
+ ** range constraint/ORDER BY terms passed in by the caller, if any. */
+ rc = idxCreateFromCons(p, pScan, p1, pTail);
+
+ /* If no range/ORDER BY passed by the caller, create a version of the
+ ** index for each range constraint. */
+ if( pTail==0 ){
+ for(pCon=pScan->pRange; rc==SQLITE_OK && pCon; pCon=pCon->pNext){
+ assert( pCon->pLink==0 );
+ if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
+ rc = idxCreateFromCons(p, pScan, p1, pCon);
+ }
+ }
+ }
+
+ return rc;
+}
+
+/*
+** Create candidate indexes in database [dbm] based on the data in
+** linked-list pScan.
+*/
+static int idxCreateCandidates(sqlite3expert *p){
+ int rc = SQLITE_OK;
+ IdxScan *pIter;
+
+ for(pIter=p->pScan; pIter && rc==SQLITE_OK; pIter=pIter->pNextScan){
+ rc = idxCreateFromWhere(p, pIter, 0);
+ if( rc==SQLITE_OK && pIter->pOrder ){
+ rc = idxCreateFromWhere(p, pIter, pIter->pOrder);
+ }
+ }
+
+ return rc;
+}
+
+/*
+** Free all elements of the linked list starting at pConstraint.
+*/
+static void idxConstraintFree(IdxConstraint *pConstraint){
+ IdxConstraint *pNext;
+ IdxConstraint *p;
+
+ for(p=pConstraint; p; p=pNext){
+ pNext = p->pNext;
+ sqlite3_free(p);
+ }
+}
+
+/*
+** Free all elements of the linked list starting from pScan up until pLast
+** (pLast is not freed).
+*/
+static void idxScanFree(IdxScan *pScan, IdxScan *pLast){
+ IdxScan *p;
+ IdxScan *pNext;
+ for(p=pScan; p!=pLast; p=pNext){
+ pNext = p->pNextScan;
+ idxConstraintFree(p->pOrder);
+ idxConstraintFree(p->pEq);
+ idxConstraintFree(p->pRange);
+ sqlite3_free(p);
+ }
+}
+
+/*
+** Free all elements of the linked list starting from pStatement up
+** until pLast (pLast is not freed).
+*/
+static void idxStatementFree(IdxStatement *pStatement, IdxStatement *pLast){
+ IdxStatement *p;
+ IdxStatement *pNext;
+ for(p=pStatement; p!=pLast; p=pNext){
+ pNext = p->pNext;
+ sqlite3_free(p->zEQP);
+ sqlite3_free(p->zIdx);
+ sqlite3_free(p);
+ }
+}
+
+/*
+** Free the linked list of IdxTable objects starting at pTab.
+*/
+static void idxTableFree(IdxTable *pTab){
+ IdxTable *pIter;
+ IdxTable *pNext;
+ for(pIter=pTab; pIter; pIter=pNext){
+ pNext = pIter->pNext;
+ sqlite3_free(pIter);
+ }
+}
+
+/*
+** Free the linked list of IdxWrite objects starting at pTab.
+*/
+static void idxWriteFree(IdxWrite *pTab){
+ IdxWrite *pIter;
+ IdxWrite *pNext;
+ for(pIter=pTab; pIter; pIter=pNext){
+ pNext = pIter->pNext;
+ sqlite3_free(pIter);
+ }
+}
+
+
+
+/*
+** This function is called after candidate indexes have been created. It
+** runs all the queries to see which indexes they prefer, and populates
+** IdxStatement.zIdx and IdxStatement.zEQP with the results.
+*/
+static int idxFindIndexes(
+ sqlite3expert *p,
+ char **pzErr /* OUT: Error message (sqlite3_malloc) */
+){
+ IdxStatement *pStmt;
+ sqlite3 *dbm = p->dbm;
+ int rc = SQLITE_OK;
+
+ IdxHash hIdx;
+ idxHashInit(&hIdx);
+
+ for(pStmt=p->pStatement; rc==SQLITE_OK && pStmt; pStmt=pStmt->pNext){
+ IdxHashEntry *pEntry;
+ sqlite3_stmt *pExplain = 0;
+ idxHashClear(&hIdx);
+ rc = idxPrintfPrepareStmt(dbm, &pExplain, pzErr,
+ "EXPLAIN QUERY PLAN %s", pStmt->zSql
+ );
+ while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
+ /* int iId = sqlite3_column_int(pExplain, 0); */
+ /* int iParent = sqlite3_column_int(pExplain, 1); */
+ /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
+ const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
+ int nDetail;
+ int i;
+
+ if( !zDetail ) continue;
+ nDetail = STRLEN(zDetail);
+
+ for(i=0; i<nDetail; i++){
+ const char *zIdx = 0;
+ if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
+ zIdx = &zDetail[i+13];
+ }else if( i+22<nDetail
+ && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0
+ ){
+ zIdx = &zDetail[i+22];
+ }
+ if( zIdx ){
+ const char *zSql;
+ int nIdx = 0;
+ while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
+ nIdx++;
+ }
+ zSql = idxHashSearch(&p->hIdx, zIdx, nIdx);
+ if( zSql ){
+ idxHashAdd(&rc, &hIdx, zSql, 0);
+ if( rc ) goto find_indexes_out;
+ }
+ break;
+ }
+ }
+
+ if( zDetail[0]!='-' ){
+ pStmt->zEQP = idxAppendText(&rc, pStmt->zEQP, "%s\n", zDetail);
+ }
+ }
+
+ for(pEntry=hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
+ pStmt->zIdx = idxAppendText(&rc, pStmt->zIdx, "%s;\n", pEntry->zKey);
+ }
+
+ idxFinalize(&rc, pExplain);
+ }
+
+ find_indexes_out:
+ idxHashClear(&hIdx);
+ return rc;
+}
+
+static int idxAuthCallback(
+ void *pCtx,
+ int eOp,
+ const char *z3,
+ const char *z4,
+ const char *zDb,
+ const char *zTrigger
+){
+ int rc = SQLITE_OK;
+ (void)z4;
+ (void)zTrigger;
+ if( eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE || eOp==SQLITE_DELETE ){
+ if( sqlite3_stricmp(zDb, "main")==0 ){
+ sqlite3expert *p = (sqlite3expert*)pCtx;
+ IdxTable *pTab;
+ for(pTab=p->pTable; pTab; pTab=pTab->pNext){
+ if( 0==sqlite3_stricmp(z3, pTab->zName) ) break;
+ }
+ if( pTab ){
+ IdxWrite *pWrite;
+ for(pWrite=p->pWrite; pWrite; pWrite=pWrite->pNext){
+ if( pWrite->pTab==pTab && pWrite->eOp==eOp ) break;
+ }
+ if( pWrite==0 ){
+ pWrite = idxMalloc(&rc, sizeof(IdxWrite));
+ if( rc==SQLITE_OK ){
+ pWrite->pTab = pTab;
+ pWrite->eOp = eOp;
+ pWrite->pNext = p->pWrite;
+ p->pWrite = pWrite;
+ }
+ }
+ }
+ }
+ }
+ return rc;
+}
+
+static int idxProcessOneTrigger(
+ sqlite3expert *p,
+ IdxWrite *pWrite,
+ char **pzErr
+){
+ static const char *zInt = UNIQUE_TABLE_NAME;
+ static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
+ IdxTable *pTab = pWrite->pTab;
+ const char *zTab = pTab->zName;
+ const char *zSql =
+ "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
+ "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
+ "ORDER BY type;";
+ sqlite3_stmt *pSelect = 0;
+ int rc = SQLITE_OK;
+ char *zWrite = 0;
+
+ /* Create the table and its triggers in the temp schema */
+ rc = idxPrintfPrepareStmt(p->db, &pSelect, pzErr, zSql, zTab, zTab);
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSelect) ){
+ const char *zCreate = (const char*)sqlite3_column_text(pSelect, 0);
+ if( zCreate==0 ) continue;
+ rc = sqlite3_exec(p->dbv, zCreate, 0, 0, pzErr);
+ }
+ idxFinalize(&rc, pSelect);
+
+ /* Rename the table in the temp schema to zInt */
+ if( rc==SQLITE_OK ){
+ char *z = sqlite3_mprintf("ALTER TABLE temp.%Q RENAME TO %Q", zTab, zInt);
+ if( z==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_exec(p->dbv, z, 0, 0, pzErr);
+ sqlite3_free(z);
+ }
+ }
+
+ switch( pWrite->eOp ){
+ case SQLITE_INSERT: {
+ int i;
+ zWrite = idxAppendText(&rc, zWrite, "INSERT INTO %Q VALUES(", zInt);
+ for(i=0; i<pTab->nCol; i++){
+ zWrite = idxAppendText(&rc, zWrite, "%s?", i==0 ? "" : ", ");
+ }
+ zWrite = idxAppendText(&rc, zWrite, ")");
+ break;
+ }
+ case SQLITE_UPDATE: {
+ int i;
+ zWrite = idxAppendText(&rc, zWrite, "UPDATE %Q SET ", zInt);
+ for(i=0; i<pTab->nCol; i++){
+ zWrite = idxAppendText(&rc, zWrite, "%s%Q=?", i==0 ? "" : ", ",
+ pTab->aCol[i].zName
+ );
+ }
+ break;
+ }
+ default: {
+ assert( pWrite->eOp==SQLITE_DELETE );
+ if( rc==SQLITE_OK ){
+ zWrite = sqlite3_mprintf("DELETE FROM %Q", zInt);
+ if( zWrite==0 ) rc = SQLITE_NOMEM;
+ }
+ }
+ }
+
+ if( rc==SQLITE_OK ){
+ sqlite3_stmt *pX = 0;
+ rc = sqlite3_prepare_v2(p->dbv, zWrite, -1, &pX, 0);
+ idxFinalize(&rc, pX);
+ if( rc!=SQLITE_OK ){
+ idxDatabaseError(p->dbv, pzErr);
+ }
+ }
+ sqlite3_free(zWrite);
+
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_exec(p->dbv, zDrop, 0, 0, pzErr);
+ }
+
+ return rc;
+}
+
+static int idxProcessTriggers(sqlite3expert *p, char **pzErr){
+ int rc = SQLITE_OK;
+ IdxWrite *pEnd = 0;
+ IdxWrite *pFirst = p->pWrite;
+
+ while( rc==SQLITE_OK && pFirst!=pEnd ){
+ IdxWrite *pIter;
+ for(pIter=pFirst; rc==SQLITE_OK && pIter!=pEnd; pIter=pIter->pNext){
+ rc = idxProcessOneTrigger(p, pIter, pzErr);
+ }
+ pEnd = pFirst;
+ pFirst = p->pWrite;
+ }
+
+ return rc;
+}
+
+
+static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
+ int rc = idxRegisterVtab(p);
+ sqlite3_stmt *pSchema = 0;
+
+ /* For each table in the main db schema:
+ **
+ ** 1) Add an entry to the p->pTable list, and
+ ** 2) Create the equivalent virtual table in dbv.
+ */
+ rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
+ "SELECT type, name, sql, 1 FROM sqlite_schema "
+ "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%%' "
+ " UNION ALL "
+ "SELECT type, name, sql, 2 FROM sqlite_schema "
+ "WHERE type = 'trigger'"
+ " AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
+ "ORDER BY 4, 1"
+ );
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
+ const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
+ const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
+ const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);
+
+ if( zType==0 || zName==0 ) continue;
+ if( zType[0]=='v' || zType[1]=='r' ){
+ if( zSql ) rc = sqlite3_exec(p->dbv, zSql, 0, 0, pzErrmsg);
+ }else{
+ IdxTable *pTab;
+ rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
+ if( rc==SQLITE_OK ){
+ int i;
+ char *zInner = 0;
+ char *zOuter = 0;
+ pTab->pNext = p->pTable;
+ p->pTable = pTab;
+
+ /* The statement the vtab will pass to sqlite3_declare_vtab() */
+ zInner = idxAppendText(&rc, 0, "CREATE TABLE x(");
+ for(i=0; i<pTab->nCol; i++){
+ zInner = idxAppendText(&rc, zInner, "%s%Q COLLATE %s",
+ (i==0 ? "" : ", "), pTab->aCol[i].zName, pTab->aCol[i].zColl
+ );
+ }
+ zInner = idxAppendText(&rc, zInner, ")");
+
+ /* The CVT statement to create the vtab */
+ zOuter = idxAppendText(&rc, 0,
+ "CREATE VIRTUAL TABLE %Q USING expert(%Q)", zName, zInner
+ );
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_exec(p->dbv, zOuter, 0, 0, pzErrmsg);
+ }
+ sqlite3_free(zInner);
+ sqlite3_free(zOuter);
+ }
+ }
+ }
+ idxFinalize(&rc, pSchema);
+ return rc;
+}
+
+struct IdxSampleCtx {
+ int iTarget;
+ double target; /* Target nRet/nRow value */
+ double nRow; /* Number of rows seen */
+ double nRet; /* Number of rows returned */
+};
+
+static void idxSampleFunc(
+ sqlite3_context *pCtx,
+ int argc,
+ sqlite3_value **argv
+){
+ struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx);
+ int bRet;
+
+ (void)argv;
+ assert( argc==0 );
+ if( p->nRow==0.0 ){
+ bRet = 1;
+ }else{
+ bRet = (p->nRet / p->nRow) <= p->target;
+ if( bRet==0 ){
+ unsigned short rnd;
+ sqlite3_randomness(2, (void*)&rnd);
+ bRet = ((int)rnd % 100) <= p->iTarget;
+ }
+ }
+
+ sqlite3_result_int(pCtx, bRet);
+ p->nRow += 1.0;
+ p->nRet += (double)bRet;
+}
+
+struct IdxRemCtx {
+ int nSlot;
+ struct IdxRemSlot {
+ int eType; /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */
+ i64 iVal; /* SQLITE_INTEGER value */
+ double rVal; /* SQLITE_FLOAT value */
+ int nByte; /* Bytes of space allocated at z */
+ int n; /* Size of buffer z */
+ char *z; /* SQLITE_TEXT/BLOB value */
+ } aSlot[1];
+};
+
+/*
+** Implementation of scalar function rem().
+*/
+static void idxRemFunc(
+ sqlite3_context *pCtx,
+ int argc,
+ sqlite3_value **argv
+){
+ struct IdxRemCtx *p = (struct IdxRemCtx*)sqlite3_user_data(pCtx);
+ struct IdxRemSlot *pSlot;
+ int iSlot;
+ assert( argc==2 );
+
+ iSlot = sqlite3_value_int(argv[0]);
+ assert( iSlot<=p->nSlot );
+ pSlot = &p->aSlot[iSlot];
+
+ switch( pSlot->eType ){
+ case SQLITE_NULL:
+ /* no-op */
+ break;
+
+ case SQLITE_INTEGER:
+ sqlite3_result_int64(pCtx, pSlot->iVal);
+ break;
+
+ case SQLITE_FLOAT:
+ sqlite3_result_double(pCtx, pSlot->rVal);
+ break;
+
+ case SQLITE_BLOB:
+ sqlite3_result_blob(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
+ break;
+
+ case SQLITE_TEXT:
+ sqlite3_result_text(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
+ break;
+ }
+
+ pSlot->eType = sqlite3_value_type(argv[1]);
+ switch( pSlot->eType ){
+ case SQLITE_NULL:
+ /* no-op */
+ break;
+
+ case SQLITE_INTEGER:
+ pSlot->iVal = sqlite3_value_int64(argv[1]);
+ break;
+
+ case SQLITE_FLOAT:
+ pSlot->rVal = sqlite3_value_double(argv[1]);
+ break;
+
+ case SQLITE_BLOB:
+ case SQLITE_TEXT: {
+ int nByte = sqlite3_value_bytes(argv[1]);
+ const void *pData = 0;
+ if( nByte>pSlot->nByte ){
+ char *zNew = (char*)sqlite3_realloc(pSlot->z, nByte*2);
+ if( zNew==0 ){
+ sqlite3_result_error_nomem(pCtx);
+ return;
+ }
+ pSlot->nByte = nByte*2;
+ pSlot->z = zNew;
+ }
+ pSlot->n = nByte;
+ if( pSlot->eType==SQLITE_BLOB ){
+ pData = sqlite3_value_blob(argv[1]);
+ if( pData ) memcpy(pSlot->z, pData, nByte);
+ }else{
+ pData = sqlite3_value_text(argv[1]);
+ memcpy(pSlot->z, pData, nByte);
+ }
+ break;
+ }
+ }
+}
+
+static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
+ int rc = SQLITE_OK;
+ const char *zMax =
+ "SELECT max(i.seqno) FROM "
+ " sqlite_schema AS s, "
+ " pragma_index_list(s.name) AS l, "
+ " pragma_index_info(l.name) AS i "
+ "WHERE s.type = 'table'";
+ sqlite3_stmt *pMax = 0;
+
+ *pnMax = 0;
+ rc = idxPrepareStmt(db, &pMax, pzErr, zMax);
+ if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
+ *pnMax = sqlite3_column_int(pMax, 0) + 1;
+ }
+ idxFinalize(&rc, pMax);
+
+ return rc;
+}
+
+static int idxPopulateOneStat1(
+ sqlite3expert *p,
+ sqlite3_stmt *pIndexXInfo,
+ sqlite3_stmt *pWriteStat,
+ const char *zTab,
+ const char *zIdx,
+ char **pzErr
+){
+ char *zCols = 0;
+ char *zOrder = 0;
+ char *zQuery = 0;
+ int nCol = 0;
+ int i;
+ sqlite3_stmt *pQuery = 0;
+ int *aStat = 0;
+ int rc = SQLITE_OK;
+
+ assert( p->iSample>0 );
+
+ /* Formulate the query text */
+ sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC);
+ while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){
+ const char *zComma = zCols==0 ? "" : ", ";
+ const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
+ const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
+ zCols = idxAppendText(&rc, zCols,
+ "%sx.%Q IS rem(%d, x.%Q) COLLATE %s", zComma, zName, nCol, zName, zColl
+ );
+ zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
+ }
+ sqlite3_reset(pIndexXInfo);
+ if( rc==SQLITE_OK ){
+ if( p->iSample==100 ){
+ zQuery = sqlite3_mprintf(
+ "SELECT %s FROM %Q x ORDER BY %s", zCols, zTab, zOrder
+ );
+ }else{
+ zQuery = sqlite3_mprintf(
+ "SELECT %s FROM temp."UNIQUE_TABLE_NAME" x ORDER BY %s", zCols, zOrder
+ );
+ }
+ }
+ sqlite3_free(zCols);
+ sqlite3_free(zOrder);
+
+ /* Formulate the query text */
+ if( rc==SQLITE_OK ){
+ sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
+ rc = idxPrepareStmt(dbrem, &pQuery, pzErr, zQuery);
+ }
+ sqlite3_free(zQuery);
+
+ if( rc==SQLITE_OK ){
+ aStat = (int*)idxMalloc(&rc, sizeof(int)*(nCol+1));
+ }
+ if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
+ IdxHashEntry *pEntry;
+ char *zStat = 0;
+ for(i=0; i<=nCol; i++) aStat[i] = 1;
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
+ aStat[0]++;
+ for(i=0; i<nCol; i++){
+ if( sqlite3_column_int(pQuery, i)==0 ) break;
+ }
+ for(/*no-op*/; i<nCol; i++){
+ aStat[i+1]++;
+ }
+ }
+
+ if( rc==SQLITE_OK ){
+ int s0 = aStat[0];
+ zStat = sqlite3_mprintf("%d", s0);
+ if( zStat==0 ) rc = SQLITE_NOMEM;
+ for(i=1; rc==SQLITE_OK && i<=nCol; i++){
+ zStat = idxAppendText(&rc, zStat, " %d", (s0+aStat[i]/2) / aStat[i]);
+ }
+ }
+
+ if( rc==SQLITE_OK ){
+ sqlite3_bind_text(pWriteStat, 1, zTab, -1, SQLITE_STATIC);
+ sqlite3_bind_text(pWriteStat, 2, zIdx, -1, SQLITE_STATIC);
+ sqlite3_bind_text(pWriteStat, 3, zStat, -1, SQLITE_STATIC);
+ sqlite3_step(pWriteStat);
+ rc = sqlite3_reset(pWriteStat);
+ }
+
+ pEntry = idxHashFind(&p->hIdx, zIdx, STRLEN(zIdx));
+ if( pEntry ){
+ assert( pEntry->zVal2==0 );
+ pEntry->zVal2 = zStat;
+ }else{
+ sqlite3_free(zStat);
+ }
+ }
+ sqlite3_free(aStat);
+ idxFinalize(&rc, pQuery);
+
+ return rc;
+}
+
+static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){
+ int rc;
+ char *zSql;
+
+ rc = sqlite3_exec(p->dbv,"DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
+ if( rc!=SQLITE_OK ) return rc;
+
+ zSql = sqlite3_mprintf(
+ "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q", zTab
+ );
+ if( zSql==0 ) return SQLITE_NOMEM;
+ rc = sqlite3_exec(p->dbv, zSql, 0, 0, 0);
+ sqlite3_free(zSql);
+
+ return rc;
+}
+
+/*
+** This function is called as part of sqlite3_expert_analyze(). Candidate
+** indexes have already been created in database sqlite3expert.dbm, this
+** function populates sqlite_stat1 table in the same database.
+**
+** The stat1 data is generated by querying the
+*/
+static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
+ int rc = SQLITE_OK;
+ int nMax =0;
+ struct IdxRemCtx *pCtx = 0;
+ struct IdxSampleCtx samplectx;
+ int i;
+ i64 iPrev = -100000;
+ sqlite3_stmt *pAllIndex = 0;
+ sqlite3_stmt *pIndexXInfo = 0;
+ sqlite3_stmt *pWrite = 0;
+
+ const char *zAllIndex =
+ "SELECT s.rowid, s.name, l.name FROM "
+ " sqlite_schema AS s, "
+ " pragma_index_list(s.name) AS l "
+ "WHERE s.type = 'table'";
+ const char *zIndexXInfo =
+ "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
+ const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";
+
+ /* If iSample==0, no sqlite_stat1 data is required. */
+ if( p->iSample==0 ) return SQLITE_OK;
+
+ rc = idxLargestIndex(p->dbm, &nMax, pzErr);
+ if( nMax<=0 || rc!=SQLITE_OK ) return rc;
+
+ rc = sqlite3_exec(p->dbm, "ANALYZE; PRAGMA writable_schema=1", 0, 0, 0);
+
+ if( rc==SQLITE_OK ){
+ int nByte = sizeof(struct IdxRemCtx) + (sizeof(struct IdxRemSlot) * nMax);
+ pCtx = (struct IdxRemCtx*)idxMalloc(&rc, nByte);
+ }
+
+ if( rc==SQLITE_OK ){
+ sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
+ rc = sqlite3_create_function(
+ dbrem, "rem", 2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
+ );
+ }
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_create_function(
+ p->db, "sample", 0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
+ );
+ }
+
+ if( rc==SQLITE_OK ){
+ pCtx->nSlot = nMax+1;
+ rc = idxPrepareStmt(p->dbm, &pAllIndex, pzErr, zAllIndex);
+ }
+ if( rc==SQLITE_OK ){
+ rc = idxPrepareStmt(p->dbm, &pIndexXInfo, pzErr, zIndexXInfo);
+ }
+ if( rc==SQLITE_OK ){
+ rc = idxPrepareStmt(p->dbm, &pWrite, pzErr, zWrite);
+ }
+
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pAllIndex) ){
+ i64 iRowid = sqlite3_column_int64(pAllIndex, 0);
+ const char *zTab = (const char*)sqlite3_column_text(pAllIndex, 1);
+ const char *zIdx = (const char*)sqlite3_column_text(pAllIndex, 2);
+ if( zTab==0 || zIdx==0 ) continue;
+ if( p->iSample<100 && iPrev!=iRowid ){
+ samplectx.target = (double)p->iSample / 100.0;
+ samplectx.iTarget = p->iSample;
+ samplectx.nRow = 0.0;
+ samplectx.nRet = 0.0;
+ rc = idxBuildSampleTable(p, zTab);
+ if( rc!=SQLITE_OK ) break;
+ }
+ rc = idxPopulateOneStat1(p, pIndexXInfo, pWrite, zTab, zIdx, pzErr);
+ iPrev = iRowid;
+ }
+ if( rc==SQLITE_OK && p->iSample<100 ){
+ rc = sqlite3_exec(p->dbv,
+ "DROP TABLE IF EXISTS temp." UNIQUE_TABLE_NAME, 0,0,0
+ );
+ }
+
+ idxFinalize(&rc, pAllIndex);
+ idxFinalize(&rc, pIndexXInfo);
+ idxFinalize(&rc, pWrite);
+
+ if( pCtx ){
+ for(i=0; i<pCtx->nSlot; i++){
+ sqlite3_free(pCtx->aSlot[i].z);
+ }
+ sqlite3_free(pCtx);
+ }
+
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
+ }
+
+ sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
+ return rc;
+}
+
+/*
+** Allocate a new sqlite3expert object.
+*/
+sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
+ int rc = SQLITE_OK;
+ sqlite3expert *pNew;
+
+ pNew = (sqlite3expert*)idxMalloc(&rc, sizeof(sqlite3expert));
+
+ /* Open two in-memory databases to work with. The "vtab database" (dbv)
+ ** will contain a virtual table corresponding to each real table in
+ ** the user database schema, and a copy of each view. It is used to
+ ** collect information regarding the WHERE, ORDER BY and other clauses
+ ** of the user's query.
+ */
+ if( rc==SQLITE_OK ){
+ pNew->db = db;
+ pNew->iSample = 100;
+ rc = sqlite3_open(":memory:", &pNew->dbv);
+ }
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_open(":memory:", &pNew->dbm);
+ if( rc==SQLITE_OK ){
+ sqlite3_db_config(pNew->dbm, SQLITE_DBCONFIG_TRIGGER_EQP, 1, (int*)0);
+ }
+ }
+
+
+ /* Copy the entire schema of database [db] into [dbm]. */
+ if( rc==SQLITE_OK ){
+ sqlite3_stmt *pSql = 0;
+ rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg,
+ "SELECT sql FROM sqlite_schema WHERE name NOT LIKE 'sqlite_%%'"
+ " AND sql NOT LIKE 'CREATE VIRTUAL %%'"
+ );
+ while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
+ const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
+ if( zSql ) rc = sqlite3_exec(pNew->dbm, zSql, 0, 0, pzErrmsg);
+ }
+ idxFinalize(&rc, pSql);
+ }
+
+ /* Create the vtab schema */
+ if( rc==SQLITE_OK ){
+ rc = idxCreateVtabSchema(pNew, pzErrmsg);
+ }
+
+ /* Register the auth callback with dbv */
+ if( rc==SQLITE_OK ){
+ sqlite3_set_authorizer(pNew->dbv, idxAuthCallback, (void*)pNew);
+ }
+
+ /* If an error has occurred, free the new object and reutrn NULL. Otherwise,
+ ** return the new sqlite3expert handle. */
+ if( rc!=SQLITE_OK ){
+ sqlite3_expert_destroy(pNew);
+ pNew = 0;
+ }
+ return pNew;
+}
+
+/*
+** Configure an sqlite3expert object.
+*/
+int sqlite3_expert_config(sqlite3expert *p, int op, ...){
+ int rc = SQLITE_OK;
+ va_list ap;
+ va_start(ap, op);
+ switch( op ){
+ case EXPERT_CONFIG_SAMPLE: {
+ int iVal = va_arg(ap, int);
+ if( iVal<0 ) iVal = 0;
+ if( iVal>100 ) iVal = 100;
+ p->iSample = iVal;
+ break;
+ }
+ default:
+ rc = SQLITE_NOTFOUND;
+ break;
+ }
+
+ va_end(ap);
+ return rc;
+}
+
+/*
+** Add an SQL statement to the analysis.
+*/
+int sqlite3_expert_sql(
+ sqlite3expert *p, /* From sqlite3_expert_new() */
+ const char *zSql, /* SQL statement to add */
+ char **pzErr /* OUT: Error message (if any) */
+){
+ IdxScan *pScanOrig = p->pScan;
+ IdxStatement *pStmtOrig = p->pStatement;
+ int rc = SQLITE_OK;
+ const char *zStmt = zSql;
+
+ if( p->bRun ) return SQLITE_MISUSE;
+
+ while( rc==SQLITE_OK && zStmt && zStmt[0] ){
+ sqlite3_stmt *pStmt = 0;
+ rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
+ if( rc==SQLITE_OK ){
+ if( pStmt ){
+ IdxStatement *pNew;
+ const char *z = sqlite3_sql(pStmt);
+ int n = STRLEN(z);
+ pNew = (IdxStatement*)idxMalloc(&rc, sizeof(IdxStatement) + n+1);
+ if( rc==SQLITE_OK ){
+ pNew->zSql = (char*)&pNew[1];
+ memcpy(pNew->zSql, z, n+1);
+ pNew->pNext = p->pStatement;
+ if( p->pStatement ) pNew->iId = p->pStatement->iId+1;
+ p->pStatement = pNew;
+ }
+ sqlite3_finalize(pStmt);
+ }
+ }else{
+ idxDatabaseError(p->dbv, pzErr);
+ }
+ }
+
+ if( rc!=SQLITE_OK ){
+ idxScanFree(p->pScan, pScanOrig);
+ idxStatementFree(p->pStatement, pStmtOrig);
+ p->pScan = pScanOrig;
+ p->pStatement = pStmtOrig;
+ }
+
+ return rc;
+}
+
+int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr){
+ int rc;
+ IdxHashEntry *pEntry;
+
+ /* Do trigger processing to collect any extra IdxScan structures */
+ rc = idxProcessTriggers(p, pzErr);
+
+ /* Create candidate indexes within the in-memory database file */
+ if( rc==SQLITE_OK ){
+ rc = idxCreateCandidates(p);
+ }else if ( rc==SQLITE_BUSY_TIMEOUT ){
+ if( pzErr )
+ *pzErr = sqlite3_mprintf("Cannot find a unique index name to propose.");
+ return rc;
+ }
+
+ /* Generate the stat1 data */
+ if( rc==SQLITE_OK ){
+ rc = idxPopulateStat1(p, pzErr);
+ }
+
+ /* Formulate the EXPERT_REPORT_CANDIDATES text */
+ for(pEntry=p->hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
+ p->zCandidates = idxAppendText(&rc, p->zCandidates,
+ "%s;%s%s\n", pEntry->zVal,
+ pEntry->zVal2 ? " -- stat1: " : "", pEntry->zVal2
+ );
+ }
+
+ /* Figure out which of the candidate indexes are preferred by the query
+ ** planner and report the results to the user. */
+ if( rc==SQLITE_OK ){
+ rc = idxFindIndexes(p, pzErr);
+ }
+
+ if( rc==SQLITE_OK ){
+ p->bRun = 1;
+ }
+ return rc;
+}
+
+/*
+** Return the total number of statements that have been added to this
+** sqlite3expert using sqlite3_expert_sql().
+*/
+int sqlite3_expert_count(sqlite3expert *p){
+ int nRet = 0;
+ if( p->pStatement ) nRet = p->pStatement->iId+1;
+ return nRet;
+}
+
+/*
+** Return a component of the report.
+*/
+const char *sqlite3_expert_report(sqlite3expert *p, int iStmt, int eReport){
+ const char *zRet = 0;
+ IdxStatement *pStmt;
+
+ if( p->bRun==0 ) return 0;
+ for(pStmt=p->pStatement; pStmt && pStmt->iId!=iStmt; pStmt=pStmt->pNext);
+ switch( eReport ){
+ case EXPERT_REPORT_SQL:
+ if( pStmt ) zRet = pStmt->zSql;
+ break;
+ case EXPERT_REPORT_INDEXES:
+ if( pStmt ) zRet = pStmt->zIdx;
+ break;
+ case EXPERT_REPORT_PLAN:
+ if( pStmt ) zRet = pStmt->zEQP;
+ break;
+ case EXPERT_REPORT_CANDIDATES:
+ zRet = p->zCandidates;
+ break;
+ }
+ return zRet;
+}
+
+/*
+** Free an sqlite3expert object.
+*/
+void sqlite3_expert_destroy(sqlite3expert *p){
+ if( p ){
+ sqlite3_close(p->dbm);
+ sqlite3_close(p->dbv);
+ idxScanFree(p->pScan, 0);
+ idxStatementFree(p->pStatement, 0);
+ idxTableFree(p->pTable);
+ idxWriteFree(p->pWrite);
+ idxHashClear(&p->hIdx);
+ sqlite3_free(p->zCandidates);
+ sqlite3_free(p);
+ }
+}
+
+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
diff --git a/ext/expert/sqlite3expert.h b/ext/expert/sqlite3expert.h
new file mode 100644
index 0000000..6048137
--- /dev/null
+++ b/ext/expert/sqlite3expert.h
@@ -0,0 +1,168 @@
+/*
+** 2017 April 07
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+*/
+#if !defined(SQLITEEXPERT_H)
+#define SQLITEEXPERT_H 1
+#include "sqlite3.h"
+
+typedef struct sqlite3expert sqlite3expert;
+
+/*
+** Create a new sqlite3expert object.
+**
+** If successful, a pointer to the new object is returned and (*pzErr) set
+** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to
+** an English-language error message. In this case it is the responsibility
+** of the caller to eventually free the error message buffer using
+** sqlite3_free().
+*/
+sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr);
+
+/*
+** Configure an sqlite3expert object.
+**
+** EXPERT_CONFIG_SAMPLE:
+** By default, sqlite3_expert_analyze() generates sqlite_stat1 data for
+** each candidate index. This involves scanning and sorting the entire
+** contents of each user database table once for each candidate index
+** associated with the table. For large databases, this can be
+** prohibitively slow. This option allows the sqlite3expert object to
+** be configured so that sqlite_stat1 data is instead generated based on a
+** subset of each table, or so that no sqlite_stat1 data is used at all.
+**
+** A single integer argument is passed to this option. If the value is less
+** than or equal to zero, then no sqlite_stat1 data is generated or used by
+** the analysis - indexes are recommended based on the database schema only.
+** Or, if the value is 100 or greater, complete sqlite_stat1 data is
+** generated for each candidate index (this is the default). Finally, if the
+** value falls between 0 and 100, then it represents the percentage of user
+** table rows that should be considered when generating sqlite_stat1 data.
+**
+** Examples:
+**
+** // Do not generate any sqlite_stat1 data
+** sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0);
+**
+** // Generate sqlite_stat1 data based on 10% of the rows in each table.
+** sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10);
+*/
+int sqlite3_expert_config(sqlite3expert *p, int op, ...);
+
+#define EXPERT_CONFIG_SAMPLE 1 /* int */
+
+/*
+** Specify zero or more SQL statements to be included in the analysis.
+**
+** Buffer zSql must contain zero or more complete SQL statements. This
+** function parses all statements contained in the buffer and adds them
+** to the internal list of statements to analyze. If successful, SQLITE_OK
+** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example
+** due to a error in the SQL - an SQLite error code is returned and (*pzErr)
+** may be set to point to an English language error message. In this case
+** the caller is responsible for eventually freeing the error message buffer
+** using sqlite3_free().
+**
+** If an error does occur while processing one of the statements in the
+** buffer passed as the second argument, none of the statements in the
+** buffer are added to the analysis.
+**
+** This function must be called before sqlite3_expert_analyze(). If a call
+** to this function is made on an sqlite3expert object that has already
+** been passed to sqlite3_expert_analyze() SQLITE_MISUSE is returned
+** immediately and no statements are added to the analysis.
+*/
+int sqlite3_expert_sql(
+ sqlite3expert *p, /* From a successful sqlite3_expert_new() */
+ const char *zSql, /* SQL statement(s) to add */
+ char **pzErr /* OUT: Error message (if any) */
+);
+
+
+/*
+** This function is called after the sqlite3expert object has been configured
+** with all SQL statements using sqlite3_expert_sql() to actually perform
+** the analysis. Once this function has been called, it is not possible to
+** add further SQL statements to the analysis.
+**
+** If successful, SQLITE_OK is returned and (*pzErr) is set to NULL. Or, if
+** an error occurs, an SQLite error code is returned and (*pzErr) set to
+** point to a buffer containing an English language error message. In this
+** case it is the responsibility of the caller to eventually free the buffer
+** using sqlite3_free().
+**
+** If an error does occur within this function, the sqlite3expert object
+** is no longer useful for any purpose. At that point it is no longer
+** possible to add further SQL statements to the object or to re-attempt
+** the analysis. The sqlite3expert object must still be freed using a call
+** sqlite3_expert_destroy().
+*/
+int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr);
+
+/*
+** Return the total number of statements loaded using sqlite3_expert_sql().
+** The total number of SQL statements may be different from the total number
+** to calls to sqlite3_expert_sql().
+*/
+int sqlite3_expert_count(sqlite3expert*);
+
+/*
+** Return a component of the report.
+**
+** This function is called after sqlite3_expert_analyze() to extract the
+** results of the analysis. Each call to this function returns either a
+** NULL pointer or a pointer to a buffer containing a nul-terminated string.
+** The value passed as the third argument must be one of the EXPERT_REPORT_*
+** #define constants defined below.
+**
+** For some EXPERT_REPORT_* parameters, the buffer returned contains
+** information relating to a specific SQL statement. In these cases that
+** SQL statement is identified by the value passed as the second argument.
+** SQL statements are numbered from 0 in the order in which they are parsed.
+** If an out-of-range value (less than zero or equal to or greater than the
+** value returned by sqlite3_expert_count()) is passed as the second argument
+** along with such an EXPERT_REPORT_* parameter, NULL is always returned.
+**
+** EXPERT_REPORT_SQL:
+** Return the text of SQL statement iStmt.
+**
+** EXPERT_REPORT_INDEXES:
+** Return a buffer containing the CREATE INDEX statements for all recommended
+** indexes for statement iStmt. If there are no new recommeded indexes, NULL
+** is returned.
+**
+** EXPERT_REPORT_PLAN:
+** Return a buffer containing the EXPLAIN QUERY PLAN output for SQL query
+** iStmt after the proposed indexes have been added to the database schema.
+**
+** EXPERT_REPORT_CANDIDATES:
+** Return a pointer to a buffer containing the CREATE INDEX statements
+** for all indexes that were tested (for all SQL statements). The iStmt
+** parameter is ignored for EXPERT_REPORT_CANDIDATES calls.
+*/
+const char *sqlite3_expert_report(sqlite3expert*, int iStmt, int eReport);
+
+/*
+** Values for the third argument passed to sqlite3_expert_report().
+*/
+#define EXPERT_REPORT_SQL 1
+#define EXPERT_REPORT_INDEXES 2
+#define EXPERT_REPORT_PLAN 3
+#define EXPERT_REPORT_CANDIDATES 4
+
+/*
+** Free an (sqlite3expert*) handle and all associated resources. There
+** should be one call to this function for each successful call to
+** sqlite3-expert_new().
+*/
+void sqlite3_expert_destroy(sqlite3expert*);
+
+#endif /* !defined(SQLITEEXPERT_H) */
diff --git a/ext/expert/test_expert.c b/ext/expert/test_expert.c
new file mode 100644
index 0000000..064c190
--- /dev/null
+++ b/ext/expert/test_expert.c
@@ -0,0 +1,220 @@
+/*
+** 2017 April 07
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+*/
+
+#if defined(SQLITE_TEST)
+
+#include "sqlite3expert.h"
+#include <assert.h>
+#include <string.h>
+
+#if defined(INCLUDE_SQLITE_TCL_H)
+# include "sqlite_tcl.h"
+#else
+# include "tcl.h"
+# ifndef SQLITE_TCLAPI
+# define SQLITE_TCLAPI
+# endif
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/*
+** Extract an sqlite3* db handle from the object passed as the second
+** argument. If successful, set *pDb to point to the db handle and return
+** TCL_OK. Otherwise, return TCL_ERROR.
+*/
+static int dbHandleFromObj(Tcl_Interp *interp, Tcl_Obj *pObj, sqlite3 **pDb){
+ Tcl_CmdInfo info;
+ if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(pObj), &info) ){
+ Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(pObj), 0);
+ return TCL_ERROR;
+ }
+
+ *pDb = *(sqlite3 **)info.objClientData;
+ return TCL_OK;
+}
+
+
+/*
+** Tclcmd: $expert sql SQL
+** $expert analyze
+** $expert count
+** $expert report STMT EREPORT
+** $expert destroy
+*/
+static int SQLITE_TCLAPI testExpertCmd(
+ void *clientData,
+ Tcl_Interp *interp,
+ int objc,
+ Tcl_Obj *CONST objv[]
+){
+ sqlite3expert *pExpert = (sqlite3expert*)clientData;
+ struct Subcmd {
+ const char *zSub;
+ int nArg;
+ const char *zMsg;
+ } aSub[] = {
+ { "sql", 1, "TABLE", }, /* 0 */
+ { "analyze", 0, "", }, /* 1 */
+ { "count", 0, "", }, /* 2 */
+ { "report", 2, "STMT EREPORT", }, /* 3 */
+ { "destroy", 0, "", }, /* 4 */
+ { 0 }
+ };
+ int iSub;
+ int rc = TCL_OK;
+ char *zErr = 0;
+
+ if( objc<2 ){
+ Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
+ return TCL_ERROR;
+ }
+ rc = Tcl_GetIndexFromObjStruct(interp,
+ objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iSub
+ );
+ if( rc!=TCL_OK ) return rc;
+ if( objc!=2+aSub[iSub].nArg ){
+ Tcl_WrongNumArgs(interp, 2, objv, aSub[iSub].zMsg);
+ return TCL_ERROR;
+ }
+
+ switch( iSub ){
+ case 0: { /* sql */
+ char *zArg = Tcl_GetString(objv[2]);
+ rc = sqlite3_expert_sql(pExpert, zArg, &zErr);
+ break;
+ }
+
+ case 1: { /* analyze */
+ rc = sqlite3_expert_analyze(pExpert, &zErr);
+ break;
+ }
+
+ case 2: { /* count */
+ int n = sqlite3_expert_count(pExpert);
+ Tcl_SetObjResult(interp, Tcl_NewIntObj(n));
+ break;
+ }
+
+ case 3: { /* report */
+ const char *aEnum[] = {
+ "sql", "indexes", "plan", "candidates", 0
+ };
+ int iEnum;
+ int iStmt;
+ const char *zReport;
+
+ if( Tcl_GetIntFromObj(interp, objv[2], &iStmt)
+ || Tcl_GetIndexFromObj(interp, objv[3], aEnum, "report", 0, &iEnum)
+ ){
+ return TCL_ERROR;
+ }
+
+ assert( EXPERT_REPORT_SQL==1 );
+ assert( EXPERT_REPORT_INDEXES==2 );
+ assert( EXPERT_REPORT_PLAN==3 );
+ assert( EXPERT_REPORT_CANDIDATES==4 );
+ zReport = sqlite3_expert_report(pExpert, iStmt, 1+iEnum);
+ Tcl_SetObjResult(interp, Tcl_NewStringObj(zReport, -1));
+ break;
+ }
+
+ default: /* destroy */
+ assert( iSub==4 );
+ Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
+ break;
+ }
+
+ if( rc!=TCL_OK ){
+ if( zErr ){
+ Tcl_SetObjResult(interp, Tcl_NewStringObj(zErr, -1));
+ }else{
+ extern const char *sqlite3ErrName(int);
+ Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+ }
+ }
+ sqlite3_free(zErr);
+ return rc;
+}
+
+static void SQLITE_TCLAPI testExpertDel(void *clientData){
+ sqlite3expert *pExpert = (sqlite3expert*)clientData;
+ sqlite3_expert_destroy(pExpert);
+}
+
+/*
+** sqlite3_expert_new DB
+*/
+static int SQLITE_TCLAPI test_sqlite3_expert_new(
+ void * clientData,
+ Tcl_Interp *interp,
+ int objc,
+ Tcl_Obj *CONST objv[]
+){
+ static int iCmd = 0;
+ sqlite3 *db;
+ char *zCmd = 0;
+ char *zErr = 0;
+ sqlite3expert *pExpert;
+ int rc = TCL_OK;
+
+ if( objc!=2 ){
+ Tcl_WrongNumArgs(interp, 1, objv, "DB");
+ return TCL_ERROR;
+ }
+ if( dbHandleFromObj(interp, objv[1], &db) ){
+ return TCL_ERROR;
+ }
+
+ zCmd = sqlite3_mprintf("sqlite3expert%d", ++iCmd);
+ if( zCmd==0 ){
+ Tcl_AppendResult(interp, "out of memory", (char*)0);
+ return TCL_ERROR;
+ }
+
+ pExpert = sqlite3_expert_new(db, &zErr);
+ if( pExpert==0 ){
+ Tcl_AppendResult(interp, zErr, (char*)0);
+ rc = TCL_ERROR;
+ }else{
+ void *p = (void*)pExpert;
+ Tcl_CreateObjCommand(interp, zCmd, testExpertCmd, p, testExpertDel);
+ Tcl_SetObjResult(interp, Tcl_NewStringObj(zCmd, -1));
+ }
+
+ sqlite3_free(zCmd);
+ sqlite3_free(zErr);
+ return rc;
+}
+
+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
+
+int TestExpert_Init(Tcl_Interp *interp){
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ struct Cmd {
+ const char *zCmd;
+ Tcl_ObjCmdProc *xProc;
+ } aCmd[] = {
+ { "sqlite3_expert_new", test_sqlite3_expert_new },
+ };
+ int i;
+
+ for(i=0; i<sizeof(aCmd)/sizeof(struct Cmd); i++){
+ struct Cmd *p = &aCmd[i];
+ Tcl_CreateObjCommand(interp, p->zCmd, p->xProc, 0, 0);
+ }
+#endif
+ return TCL_OK;
+}
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 05:30:26 +0000