From 48f7e6439568e5d665f622e2973becc50a86b64a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 24 Sep 2007 03:12:23 +0000 Subject: [PATCH] Simplify and rename some GUC variables, per various recent discussions: * stats_start_collector goes away; we always start the collector process, unless prevented by a problem with setting up the stats UDP socket. * stats_reset_on_server_start goes away; it seems useless in view of the availability of pg_stat_reset(). * stats_block_level and stats_row_level are merged into a single variable "track_counts", which controls all reports sent to the collector process. * stats_command_string is renamed to track_activities. * log_autovacuum is renamed to log_autovacuum_min_duration to better reflect its meaning. The log_autovacuum change is not a compatibility issue since it didn't exist before 8.3 anyway. The other changes need to be release-noted. --- doc/src/sgml/config.sgml | 150 ++++++------------ doc/src/sgml/maintenance.sgml | 17 +- doc/src/sgml/monitoring.sgml | 48 ++---- doc/src/sgml/release.sgml | 5 +- src/backend/commands/analyze.c | 12 +- src/backend/commands/vacuumlazy.c | 10 +- src/backend/postmaster/autovacuum.c | 28 +--- src/backend/postmaster/pgstat.c | 94 +++-------- src/backend/utils/misc/guc.c | 66 +++----- src/backend/utils/misc/postgresql.conf.sample | 19 +-- src/include/pgstat.h | 65 ++++---- src/include/postmaster/autovacuum.h | 4 +- src/test/regress/expected/stats.out | 9 +- src/test/regress/sql/stats.sql | 6 +- 14 files changed, 182 insertions(+), 351 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index f275efb1c3..fd2fd5d71b 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1,4 +1,4 @@ - + Server Configuration @@ -3186,30 +3186,19 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; Query and Index Statistics Collector - These parameters control a server-wide statistics collection feature. + 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 for more information. - - - As of PostgreSQL 8.2, - stats_command_string controls a separate data - collection mechanism that can be turned on or off independently - of whether the statistics-collection subprocess is running. - The subprocess is only needed to support collection of - block-level or row-level statistics. - - - - - stats_command_string (boolean) + + track_activities (boolean) - stats_command_string configuration parameter + track_activities configuration parameter @@ -3225,6 +3214,21 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; + + track_counts (boolean) + + track_counts configuration parameter + + + + 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. + + + + update_process_title (boolean) @@ -3234,75 +3238,13 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; Enables updating of the process title every time a new SQL command is received by the server. The process title is typically viewed - by the ps command or in Windows using the Process - Explorer. Only superusers can change this setting. - - - - - - stats_start_collector (boolean) - - stats_start_collector configuration parameter - - - - Controls whether the server should start the - statistics-collection subprocess. This is on by default, but - can be turned off if you know you have no interest in - collecting statistics or running autovacuum. - This parameter can only be set at server start, because the collection - subprocess cannot be started or stopped on-the-fly. (However, the - extent to which statistics are actually gathered can be changed while - the server is running, so long as the subprocess exists.) - - - - - - stats_block_level (boolean) - - stats_block_level configuration parameter - - - - Enables the collection of block-level statistics on database - activity. This parameter is off by default. + by the ps command, + or in Windows by using the Process Explorer. Only superusers can change this setting. - - stats_row_level (boolean) - - stats_row_level configuration parameter - - - - Enables the collection of row-level statistics on database - activity. This parameter is on by default, because the autovacuum - daemon needs the collected information. - Only superusers can change this setting. - - - - - - stats_reset_on_server_start (boolean) - - stats_reset_on_server_start configuration parameter - - - - If on, collected block-level and row-level statistics are zeroed out - whenever the server is restarted. If off, statistics are accumulated - across server restarts. This parameter is off by default. - This parameter can only be set at server start. - - - - @@ -3369,21 +3311,40 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; Controls whether the server should run the - autovacuum launcher daemon. This is on by default. - stats_start_collector and stats_row_level - must also be turned on for autovacuum to work. + autovacuum launcher daemon. This is on by default; however, + must also be turned on for + autovacuum to work. This parameter can only be set in the postgresql.conf file or on the server command line. Note that even when this parameter is disabled, the system - will periodically launch autovacuum processes in order to + will launch autovacuum processes if necessary to prevent transaction ID wraparound. See for more information. + + log_autovacuum_min_duration (integer) + + log_autovacuum_min_duration configuration parameter + + + + Causes each action executed by autovacuum to be logged if it ran for at + least the specified number of milliseconds. Setting this to zero logs + all autovacuum actions. Minus-one (the default) disables logging + autovacuum actions. For example, if you set this to + 250ms then all automatic vacuums and analyzes that run + 250ms or longer will be logged. Enabling this parameter can be helpful + in tracking autovacuum activity. This setting can only be set in + the postgresql.conf file or on the server command line. + + + + autovacuum_max_workers (integer) @@ -3393,26 +3354,7 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; Specifies the maximum number of autovacuum processes (other than the autovacuum launcher) which may be running at any one time. The default - is three (3). This parameter can only be set in - the postgresql.conf file or on the server command line. - - - - - - log_autovacuum (integer) - - log_autovacuum configuration parameter - - - - Causes each action executed by autovacuum to be logged if it ran for at - least the specified number of milliseconds. Setting this to zero logs - all autovacuum actions. Minus-one (the default) disables logging - autovacuum actions. For example, if you set this to - 250ms then all vacuums and analyzes that run - 250ms or longer will be logged. Enabling this parameter can be helpful - in tracking autovacuum activity. This setting can only be set in + is three. This parameter can only be set in the postgresql.conf file or on the server command line. diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index 40eecdc376..3d87eeb329 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -1,4 +1,4 @@ - + Routine Database Maintenance Tasks @@ -203,7 +203,7 @@ - Updating planner statistics + Updating Planner Statistics statistics @@ -279,7 +279,7 @@ - Preventing transaction ID wraparound failures + Preventing Transaction ID Wraparound Failures transaction ID @@ -460,7 +460,7 @@ HINT: Stop the postmaster and use a standalone backend to VACUUM in "mydb". - The auto-vacuum daemon + The Auto-Vacuum Daemon autovacuum @@ -473,10 +473,9 @@ HINT: Stop the postmaster and use a standalone backend to VACUUM in "mydb". VACUUM and ANALYZE commands. When enabled, autovacuum checks for tables that have had a large number of inserted, updated or deleted - tuples. These checks use the row-level statistics collection facility; + tuples. These checks use the statistics collection facility; therefore, autovacuum cannot be used unless and are set to true. + linkend="guc-track-counts"> is set to true. In the default configuration, autovacuuming is enabled and the related configuration parameters are appropriately set. @@ -497,8 +496,8 @@ HINT: Stop the postmaster and use a standalone backend to VACUUM in "mydb". eligible for vacuuming in a short amount of time, all autovacuum workers may end up vacuuming those tables for a very long time. This would result in other tables and databases not being vacuumed until a worker became - available. There is also not a limit on how many workers might be in a - single database, but workers do try and avoid repeating work that has + available. There is not a limit on how many workers might be in a + single database, but workers do try to avoid repeating work that has already been done by other workers. Note that the number of running workers does not count towards the nor the limits. diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index c00d1a0d5a..a2536c9190 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1,4 +1,4 @@ - + Monitoring Database Activity @@ -117,14 +117,15 @@ postgres: user database host PostgreSQL's statistics collector is a subsystem that supports collection and reporting of information about server activity. Presently, the collector can count accesses to tables - and indexes in both disk-block and individual-row terms. + and indexes in both disk-block and individual-row terms. It also tracks + total numbers of rows in each table, and the last vacuum and analyze times + for each table. PostgreSQL also supports determining the exact command currently being executed by other server processes. This is an - independent facility that can be enabled or disabled whether or not - block-level and row-level statistics are being collected. + independent facility that does not depend on the collector process. @@ -139,31 +140,14 @@ postgres: user database host - The parameter must be - set to true for the statistics collector to be launched - at all. This is the default and recommended setting, but it can be - turned off if you have no interest in statistics and want to - squeeze out every last drop of overhead. (The savings is likely to - be small, however.) Note that this option cannot be changed while - the server is running. + The parameter controls whether + information is actually sent to the collector process and thus determines + whether any run-time overhead occurs for event counting. - The parameters and control how much information is - actually sent to the collector and thus determine how much run-time - overhead occurs. These respectively determine whether a server - process tracks disk-block-level access - statistics and row-level access statistics and sends these to the collector. - Additionally, per-database transaction commit and abort statistics - are collected if either of these parameters are set. - - - - The parameter enables monitoring + The parameter enables monitoring of the current command being executed by any server process. - The statistics collector subprocess need not be running to enable this - feature. @@ -190,13 +174,13 @@ postgres: user database host When using the statistics to monitor current activity, it is important to realize that the information does not update instantaneously. - Each individual server process transmits new block and row access counts to + Each individual server process transmits new statistical counts to the collector just before going idle; so a query or transaction still in progress does not affect the displayed totals. Also, the collector itself emits a new report at most once per PGSTAT_STAT_INTERVAL milliseconds (500 unless altered while building the server). So the displayed information lags behind actual activity. However, current-query - information collected by stats_command_string is + information collected by track_activities is always up-to-date. @@ -240,7 +224,7 @@ postgres: user database host stats_command_string has been turned off. + track_activities has been turned off. Furthermore, these columns are only visible if the user examining the view is a superuser or the same as the user owning the process being reported on. @@ -715,7 +699,7 @@ postgres: user database host stats_command_string is on) + track_activities is on) @@ -726,7 +710,7 @@ postgres: user database host stats_command_string is on) + track_activities is on) @@ -738,7 +722,7 @@ postgres: user database host stats_command_string is on) + track_activities is on) @@ -750,7 +734,7 @@ postgres: user database host stats_command_string is on) + track_activities is on) diff --git a/doc/src/sgml/release.sgml b/doc/src/sgml/release.sgml index a68dd592d6..e287770a60 100644 --- a/doc/src/sgml/release.sgml +++ b/doc/src/sgml/release.sgml @@ -1,4 +1,4 @@ - +