These parameters control server-wide statistics collection
features. When statistics collection is enabled, the data that is
produced can be accessed via the
pg_statio family of system views. Refer to
for more information.
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.
Specifies the number of bytes reserved to track the currently
executing command for each active session, for the
query field. The default value is 1024. This
parameter can only be set at server start.
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.
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
superusers can change this setting.
Enables tracking of function call counts and time used. Specify
pl to track only procedural-language
all to also track SQL and C
language functions. The default is
none, which disables function statistics tracking.
Only superusers can change this setting.
SQL-language functions that are simple enough to be “inlined” into the calling query will not be tracked, regardless of this setting.
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
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
For each query, output performance statistics of the respective
module to the server log. This is a crude profiling instrument,
similar to the Unix
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
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