54.24. pg_settings

54.24. `pg_settings`
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54.24. `pg_settings`

+ The view pg_settings provides access to + run-time parameters of the server. It is essentially an alternative + interface to the SHOW + and SET commands. + It also provides access to some facts about each parameter that are + not directly available from SHOW, such as minimum and + maximum values. +

Table 54.24. pg_settings Columns

+ Column Type + + + Description +
+ `name` `text` + + + Run-time configuration parameter name +
+ `setting` `text` + + + Current value of the parameter +
+ `unit` `text` + + + Implicit unit of the parameter +
+ `category` `text` + + + Logical group of the parameter +
+ `short_desc` `text` + + + A brief description of the parameter +
+ `extra_desc` `text` + + + Additional, more detailed, description of the parameter +
+ `context` `text` + + + Context required to set the parameter's value (see below) +
+ `vartype` `text` + + + Parameter type (`bool`, `enum`, + `integer`, `real`, or `string`) +
+ `source` `text` + + + Source of the current parameter value +
+ `min_val` `text` + + + Minimum allowed value of the parameter (null for non-numeric + values) +
+ `max_val` `text` + + + Maximum allowed value of the parameter (null for non-numeric + values) +
+ `enumvals` `text[]` + + + Allowed values of an enum parameter (null for non-enum + values) +
+ `boot_val` `text` + + + Parameter value assumed at server startup if the parameter is + not otherwise set +
+ `reset_val` `text` + + + Value that `RESET` would reset the parameter to + in the current session +
+ `sourcefile` `text` + + + Configuration file the current value was set in (null for + values set from sources other than configuration files, or when + examined by a user who neither is a superuser nor has privileges of + `pg_read_all_settings`); helpful when using + `include` directives in configuration files +
+ `sourceline` `int4` + + + Line number within the configuration file the current value was + set at (null for values set from sources other than configuration files, + or when examined by a user who neither is a superuser nor has privileges of + `pg_read_all_settings`). +
+ `pending_restart` `bool` + + + `true` if the value has been changed in the + configuration file but needs a restart; or `false` + otherwise. +

+ Column Type +

+ Description +

+ name text +

+ Run-time configuration parameter name +

+ setting text +

+ Current value of the parameter +

+ unit text +

+ Implicit unit of the parameter +

+ category text +

+ Logical group of the parameter +

+ short_desc text +

+ A brief description of the parameter +

+ extra_desc text +

+ Additional, more detailed, description of the parameter +

+ context text +

+ Context required to set the parameter's value (see below) +

+ vartype text +

+ Parameter type (bool, enum, + integer, real, or string) +

+ source text +

+ Source of the current parameter value +

+ min_val text +

+ Minimum allowed value of the parameter (null for non-numeric + values) +

+ max_val text +

+ Maximum allowed value of the parameter (null for non-numeric + values) +

+ enumvals text[] +

+ Allowed values of an enum parameter (null for non-enum + values) +

+ boot_val text +

+ Parameter value assumed at server startup if the parameter is + not otherwise set +

+ reset_val text +

+ Value that RESET would reset the parameter to + in the current session +

+ sourcefile text +

+ Configuration file the current value was set in (null for + values set from sources other than configuration files, or when + examined by a user who neither is a superuser nor has privileges of + pg_read_all_settings); helpful when using + include directives in configuration files +

+ sourceline int4 +

+ Line number within the configuration file the current value was + set at (null for values set from sources other than configuration files, + or when examined by a user who neither is a superuser nor has privileges of + pg_read_all_settings). +

+ pending_restart bool +

+ true if the value has been changed in the + configuration file but needs a restart; or false + otherwise. +

+ There are several possible values of context. + In order of decreasing difficulty of changing the setting, they are: +

internal: + These settings cannot be changed directly; they reflect internally + determined values. Some of them may be adjustable by rebuilding the + server with different configuration options, or by changing options + supplied to initdb. +
postmaster: + These settings can only be applied when the server starts, so any change + requires restarting the server. Values for these settings are typically + stored in the postgresql.conf file, or passed on + the command line when starting the server. Of course, settings with any + of the lower context types can also be + set at server start time. +
sighup: + Changes to these settings can be made in + postgresql.conf without restarting the server. + Send a SIGHUP signal to the postmaster to + cause it to re-read postgresql.conf and apply + the changes. The postmaster will also forward the + SIGHUP signal to its child processes so that + they all pick up the new value. +
superuser-backend: + Changes to these settings can be made in + postgresql.conf without restarting the server. + They can also be set for a particular session in the connection request + packet (for example, via libpq's PGOPTIONS + environment variable), but only if the connecting user is a superuser + or has been granted the appropriate SET privilege. + However, these settings never change in a session after it is started. + If you change them in postgresql.conf, send a + SIGHUP signal to the postmaster to cause it to + re-read postgresql.conf. The new values will only + affect subsequently-launched sessions. +
backend: + Changes to these settings can be made in + postgresql.conf without restarting the server. + They can also be set for a particular session in the connection request + packet (for example, via libpq's PGOPTIONS + environment variable); any user can make such a change for their session. + However, these settings never change in a session after it is started. + If you change them in postgresql.conf, send a + SIGHUP signal to the postmaster to cause it to + re-read postgresql.conf. The new values will only + affect subsequently-launched sessions. +
superuser: + These settings can be set from postgresql.conf, + or within a session via the SET command; but only superusers + and users with the appropriate SET privilege + can change them via SET. Changes in + postgresql.conf will affect existing sessions + only if no session-local value has been established with SET. +
user: + These settings can be set from postgresql.conf, + or within a session via the SET command. Any user is + allowed to change their session-local value. Changes in + postgresql.conf will affect existing sessions + only if no session-local value has been established with SET. +

+ See Section 20.1 for more information about the various + ways to change these parameters. +

+ This view cannot be inserted into or deleted from, but it can be updated. An + UPDATE applied to a row of pg_settings + is equivalent to executing the SET command on that named + parameter. The change only affects the value used by the current + session. If an UPDATE is issued within a transaction + that is later aborted, the effects of the UPDATE command + disappear when the transaction is rolled back. Once the surrounding + transaction is committed, the effects will persist until the end of the + session, unless overridden by another UPDATE or + SET. +

+ This view does not + display customized options + unless the extension module that defines them has been loaded by the + backend process executing the query (e.g., via a mention in + shared_preload_libraries, + a call to a C function in the extension, or the + LOAD command). + For example, since archive modules + are normally loaded only by the archiver process not regular sessions, + this view will not display any customized options defined by such modules + unless special action is taken to load them into the backend process + executing the query. +

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