diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index f2f4b1d13d8..5a25b0308ed 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -5180,8 +5180,10 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; These settings control the behavior of the autovacuum - feature. Refer to for - more information. + feature. Refer to for more information. + Note that many of these settings can be overridden on a per-table + basis; see . @@ -5199,7 +5201,8 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; must also be enabled for autovacuum to work. This parameter can only be set in the postgresql.conf - file or on the server command line. + file or on the server command line; however, autovacuuming can be + disabled for individual tables by changing table storage parameters. Note that even when this parameter is disabled, the system @@ -5227,8 +5230,10 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; set to any value other than -1, a message will be logged if an autovacuum action is skipped due to the existence of a conflicting lock. 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. + in tracking autovacuum activity. This parameter can only be set in + the postgresql.conf file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5242,7 +5247,7 @@ 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 + autovacuum launcher) that may be running at any one time. The default is three. This parameter can only be set at server start. @@ -5279,9 +5284,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; to trigger a VACUUM in any one table. The default is 50 tuples. This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5298,9 +5303,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; needed to trigger an ANALYZE in any one table. The default is 50 tuples. This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5318,9 +5323,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; when deciding whether to trigger a VACUUM. The default is 0.2 (20% of table size). This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5338,9 +5343,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; when deciding whether to trigger an ANALYZE. The default is 0.1 (10% of table size). This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5367,7 +5372,7 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; is a relatively low 200 million transactions. This parameter can only be set at server start, but the setting can be reduced for individual tables by - changing storage parameters. + changing table storage parameters. For more information see . @@ -5394,8 +5399,8 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; pg_multixact/members and pg_multixact/offsets subdirectories, which is why the default is a relatively low 400 million multixacts. - This parameter can only be set at server start, but the setting - can be reduced for individual tables by changing storage parameters. + This parameter can only be set at server start, but the setting can + be reduced for individual tables by changing table storage parameters. For more information see . @@ -5414,9 +5419,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; value will be used. The default value is 20 milliseconds. This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -5434,12 +5439,12 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; default), the regular value will be used. Note that the value is distributed proportionally among the running autovacuum - workers, if there is more than one, so that the sum of the limits of - each worker never exceeds the limit on this variable. + workers, if there is more than one, so that the sum of the limits for + each worker does not exceed the value of this variable. This parameter can only be set in the postgresql.conf - file or on the server command line. - This setting can be overridden for individual tables by - changing storage parameters. + file or on the server command line; + but the setting can be overridden for individual tables by + changing table storage parameters. @@ -6018,7 +6023,7 @@ SET XML OPTION { DOCUMENT | CONTENT }; the entries in it to the main GIN data structure in bulk. The default is four megabytes (4MB). This setting can be overridden for individual GIN indexes by changing - storage parameters. + index storage parameters. See and for more information. diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index b5d405024d8..5204b34c75a 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -705,15 +705,15 @@ HINT: Stop the postmaster and vacuum that database in single-user mode. the next database will be processed as soon as the first worker finishes. Each worker process will check each table within its database and execute VACUUM and/or ANALYZE as needed. - log_autovacuum_min_duration can be used to monitor - autovacuum activity. + can be set to monitor + autovacuum workers' activity. If several large tables all become eligible for vacuuming in a short amount of time, all autovacuum workers might become occupied with vacuuming those tables for a long period. This would result - in other tables and databases not being vacuumed until a worker became + in other tables and databases not being vacuumed until a worker becomes available. There is no 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 @@ -767,45 +767,24 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu The default thresholds and scale factors are taken from postgresql.conf, but it is possible to override them - on a table-by-table basis; see + (and many other autovacuum control parameters) on a per-table basis; see for more information. - If a setting - has been changed via storage parameters, that value is used; otherwise the - global settings are used. See for - more details on the global settings. + If a setting has been changed via a table's storage parameters, that value + is used when processing that table; otherwise the global settings are + used. See for more details on + the global settings. - Besides the base threshold values and scale factors, there are six - more autovacuum parameters that can be set for each table via - storage parameters. - The first parameter, autovacuum_enabled, - can be set to false to instruct the autovacuum daemon - to skip that particular table entirely. In this case - autovacuum will only touch the table if it must do so - to prevent transaction ID wraparound. - Another two parameters, - autovacuum_vacuum_cost_delay and - autovacuum_vacuum_cost_limit, are used to set - table-specific values for the cost-based vacuum delay feature - (see ). - autovacuum_freeze_min_age, - autovacuum_freeze_max_age and - autovacuum_freeze_table_age are used to set - values for , - and - respectively. - - - - When multiple workers are running, the cost delay parameters are + When multiple workers are running, the autovacuum cost delay parameters + (see ) are balanced among all the running workers, so that the total I/O impact on the system is the same regardless of the number of workers actually running. However, any workers processing tables whose - autovacuum_vacuum_cost_delay or - autovacuum_vacuum_cost_limit have been set are not considered - in the balancing algorithm. + per-table autovacuum_vacuum_cost_delay or + autovacuum_vacuum_cost_limit storage parameters have been set + are not considered in the balancing algorithm. diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index a2d0b0cbe1e..f0c94d591ef 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -878,14 +878,14 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI Storage parameters for indexes are documented in . The storage parameters currently - available for tables are listed below. For each parameter, unless noted, - there is an additional parameter with the same name prefixed with - toast., which can be used to control the behavior of the + available for tables are listed below. For many of these parameters, as + shown, there is an additional parameter with the same name prefixed with + toast., which controls the behavior of the table's secondary TOAST table, if any (see for more information about TOAST). - Note that the TOAST table uses the parameter values defined for - the main table, for each parameter applicable to TOAST tables and - for which no value is set in the TOAST table itself. + If a table parameter value is set and the + equivalent toast. parameter is not, the TOAST table + will use the table's parameter value. @@ -912,22 +912,19 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_enabled, toast.autovacuum_enabled (boolean) - Enables or disables the autovacuum daemon on a particular table. - If true, the autovacuum daemon will initiate a VACUUM operation - on a particular table when the number of updated or deleted tuples exceeds - autovacuum_vacuum_threshold plus - autovacuum_vacuum_scale_factor times the number of live tuples - currently estimated to be in the relation. - Similarly, it will initiate an ANALYZE operation when the - number of inserted, updated or deleted tuples exceeds - autovacuum_analyze_threshold plus - autovacuum_analyze_scale_factor times the number of live tuples - currently estimated to be in the relation. + Enables or disables the autovacuum daemon for a particular table. + If true, the autovacuum daemon will perform automatic VACUUM + and/or ANALYZE operations on this table following the rules + discussed in . If false, this table will not be autovacuumed, except to prevent - transaction Id wraparound. See for + transaction ID wraparound. See for more about wraparound prevention. - Observe that this variable inherits its value from the setting. + Note that the autovacuum daemon does not run at all (except to prevent + transaction ID wraparound) if the + parameter is false; setting individual tables' storage parameters does + not override that. Therefore there is seldom much point in explicitly + setting this storage parameter to true, only + to false. @@ -936,8 +933,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_vacuum_threshold, toast.autovacuum_vacuum_threshold (integer) - Minimum number of updated or deleted tuples before initiate a - VACUUM operation on a particular table. + Per-table value for + parameter. @@ -946,8 +943,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_vacuum_scale_factor, toast.autovacuum_vacuum_scale_factor (float4) - Multiplier for reltuples to add to - autovacuum_vacuum_threshold. + Per-table value for + parameter. @@ -956,8 +953,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_analyze_threshold (integer) - Minimum number of inserted, updated, or deleted tuples before initiate an - ANALYZE operation on a particular table. + Per-table value for + parameter. @@ -966,8 +963,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_analyze_scale_factor (float4) - Multiplier for reltuples to add to - autovacuum_analyze_threshold. + Per-table value for + parameter. @@ -976,7 +973,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_vacuum_cost_delay, toast.autovacuum_vacuum_cost_delay (integer) - Custom parameter. + Per-table value for + parameter. @@ -985,7 +983,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_vacuum_cost_limit, toast.autovacuum_vacuum_cost_limit (integer) - Custom parameter. + Per-table value for + parameter. @@ -994,10 +993,11 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_freeze_min_age, toast.autovacuum_freeze_min_age (integer) - Custom parameter. Note that - autovacuum will ignore attempts to set a per-table - autovacuum_freeze_min_age larger than half the system-wide - setting. + Per-table value for + parameter. Note that autovacuum will ignore + per-table autovacuum_freeze_min_age parameters that are + larger than half the + system-wide setting. @@ -1006,10 +1006,10 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_freeze_max_age, toast.autovacuum_freeze_max_age (integer) - Custom parameter. Note that - autovacuum will ignore attempts to set a per-table - autovacuum_freeze_max_age larger than the system-wide setting - (it can only be set smaller). + Per-table value for + parameter. Note that autovacuum will ignore + per-table autovacuum_freeze_max_age parameters that are + larger than the system-wide setting (it can only be set smaller). @@ -1018,7 +1018,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_freeze_table_age, toast.autovacuum_freeze_table_age (integer) - Custom parameter. + Per-table value for + parameter. @@ -1027,9 +1028,10 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_multixact_freeze_min_age, toast.autovacuum_multixact_freeze_min_age (integer) - Custom parameter. - Note that autovacuum will ignore attempts to set a per-table - autovacuum_multixact_freeze_min_age larger than half the + Per-table value for + parameter. Note that autovacuum will ignore + per-table autovacuum_multixact_freeze_min_age parameters + that are larger than half the system-wide setting. @@ -1040,10 +1042,12 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_multixact_freeze_max_age, toast.autovacuum_multixact_freeze_max_age (integer) - Custom parameter. Note - that autovacuum will ignore attempts to set a per-table - autovacuum_multixact_freeze_max_age larger than the - system-wide setting (it can only be set smaller). + Per-table value + for parameter. + Note that autovacuum will ignore + per-table autovacuum_multixact_freeze_max_age parameters + that are larger than the system-wide setting (it can only be set + smaller). @@ -1052,7 +1056,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI autovacuum_multixact_freeze_table_age, toast.autovacuum_multixact_freeze_table_age (integer) - Custom parameter. + Per-table value + for parameter. @@ -1061,7 +1066,8 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI log_autovacuum_min_duration, toast.log_autovacuum_min_duration (integer) - Custom parameter. + Per-table value for + parameter. @@ -1070,7 +1076,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI user_catalog_table (boolean) - Declare a table as an additional catalog table, e.g. for the purpose of + Declare the table as an additional catalog table for purposes of logical replication. See for details. This parameter cannot be set for TOAST tables.