19.9. Run-time Statistics

19.9. Run-time Statistics
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19.9.1. Query and Index Statistics Collector
19.9.2. Statistics Monitoring

19.9.1. Query and Index Statistics Collector

+ These parameters control server-wide statistics collection features. + When statistics collection is enabled, the data that is produced can be + accessed via the pg_stat and + pg_statio family of system views. + Refer to Chapter 27 for more information. +

track_activities (boolean) + +: + Enables the collection of information on the currently + executing command of each session, along with the time when + that command began execution. This parameter is on by + default. Note that even when enabled, this information is not + visible to all users, only to superusers and the user owning + the session being reported on, so it should not represent a + security risk. + Only superusers can change this setting. +
track_activity_query_size (integer) + +: + Specifies the amount of memory reserved to store the text of the + currently executing command for each active session, for the + pg_stat_activity.query field. + If this value is specified without units, it is taken as bytes. + The default value is 1024 bytes. + This parameter can only be set at server start. +
track_counts (boolean) + +: + Enables collection of statistics on database activity. + This parameter is on by default, because the autovacuum + daemon needs the collected information. + Only superusers can change this setting. +
track_io_timing (boolean) + +: + Enables timing of database I/O calls. This parameter is off by + default, because it will repeatedly query the operating system for + the current time, which may cause significant overhead on some + platforms. You can use the pg_test_timing tool to + measure the overhead of timing on your system. + I/O timing information is + displayed in + pg_stat_database, in the output of + EXPLAIN when the BUFFERS option is + used, and by pg_stat_statements. Only superusers can + change this setting. +
track_functions (enum) + +: + Enables tracking of function call counts and time used. Specify + pl to track only procedural-language functions, + all to also track SQL and C language functions. + The default is none, which disables function + statistics tracking. Only superusers can change this setting. +
Note
+ SQL-language functions that are simple enough to be “inlined” + into the calling query will not be tracked, regardless of this + setting. +
stats_temp_directory (string) + +: + Sets the directory to store temporary statistics data in. This can be + a path relative to the data directory or an absolute path. The default + is pg_stat_tmp. Pointing this at a RAM-based + file system will decrease physical I/O requirements and can lead to + improved performance. + This parameter can only be set in the postgresql.conf + file or on the server command line. +

19.9.2. Statistics Monitoring

log_statement_stats (boolean) + + log_parser_stats (boolean) + + log_planner_stats (boolean) + + log_executor_stats (boolean) + +: + For each query, output performance statistics of the respective + module to the server log. This is a crude profiling + instrument, similar to the Unix getrusage() operating + system facility. log_statement_stats reports total + statement statistics, while the others report per-module statistics. + log_statement_stats cannot be enabled together with + any of the per-module options. All of these options are disabled by + default. Only superusers can change these settings. +

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19.8. Error Reporting and Logging	Home	19.10. Automatic Vacuuming

19.9. Run-time Statistics

19.9.1. Query and Index Statistics Collector

Note

19.9.2. Statistics Monitoring