SET(7)

NAME

   SET - change a run-time parameter

SYNOPSIS

   SET [ SESSION | LOCAL ] configuration_parameter { TO | = } { value | 'value' | DEFAULT }
   SET [ SESSION | LOCAL ] TIME ZONE { timezone | LOCAL | DEFAULT }

DESCRIPTION

   The SET command changes run-time configuration parameters. Many of the
   run-time parameters listed in Chapter 18, Server Configuration, in the
   documentation can be changed on-the-fly with SET. (But some require
   superuser privileges to change, and others cannot be changed after
   server or session start.)  SET only affects the value used by the
   current session.

   If SET (or equivalently SET SESSION) is issued within a transaction
   that is later aborted, the effects of the SET 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 SET.

   The effects of SET LOCAL last only till the end of the current
   transaction, whether committed or not. A special case is SET followed
   by SET LOCAL within a single transaction: the SET LOCAL value will be
   seen until the end of the transaction, but afterwards (if the
   transaction is committed) the SET value will take effect.

   The effects of SET or SET LOCAL are also canceled by rolling back to a
   savepoint that is earlier than the command.

   If SET LOCAL is used within a function that has a SET option for the
   same variable (see CREATE FUNCTION (CREATE_FUNCTION(7))), the effects
   of the SET LOCAL command disappear at function exit; that is, the value
   in effect when the function was called is restored anyway. This allows
   SET LOCAL to be used for dynamic or repeated changes of a parameter
   within a function, while still having the convenience of using the SET
   option to save and restore the caller's value. However, a regular SET
   command overrides any surrounding function's SET option; its effects
   will persist unless rolled back.

       Note
       In PostgreSQL versions 8.0 through 8.2, the effects of a SET LOCAL
       would be canceled by releasing an earlier savepoint, or by
       successful exit from a PL/pgSQL exception block. This behavior has
       been changed because it was deemed unintuitive.

PARAMETERS

   SESSION
       Specifies that the command takes effect for the current session.
       (This is the default if neither SESSION nor LOCAL appears.)

   LOCAL
       Specifies that the command takes effect for only the current
       transaction. After COMMIT or ROLLBACK, the session-level setting
       takes effect again. Issuing this outside of a transaction block
       emits a warning and otherwise has no effect.

   configuration_parameter
       Name of a settable run-time parameter. Available parameters are
       documented in Chapter 18, Server Configuration, in the
       documentation and below.

   value
       New value of parameter. Values can be specified as string
       constants, identifiers, numbers, or comma-separated lists of these,
       as appropriate for the particular parameter.  DEFAULT can be
       written to specify resetting the parameter to its default value
       (that is, whatever value it would have had if no SET had been
       executed in the current session).

   Besides the configuration parameters documented in Chapter 18, Server
   Configuration, in the documentation, there are a few that can only be
   adjusted using the SET command or that have a special syntax:

   SCHEMA
       SET SCHEMA 'value' is an alias for SET search_path TO value. Only
       one schema can be specified using this syntax.

   NAMES
       SET NAMES value is an alias for SET client_encoding TO value.

   SEED
       Sets the internal seed for the random number generator (the
       function random). Allowed values are floating-point numbers between
       -1 and 1, which are then multiplied by 231-1.

       The seed can also be set by invoking the function setseed:

           SELECT setseed(value);

   TIME ZONE
       SET TIME ZONE value is an alias for SET timezone TO value. The
       syntax SET TIME ZONE allows special syntax for the time zone
       specification. Here are examples of valid values:

       'PST8PDT'
           The time zone for Berkeley, California.

       'Europe/Rome'
           The time zone for Italy.

       -7
           The time zone 7 hours west from UTC (equivalent to PDT).
           Positive values are east from UTC.

       INTERVAL '-08:00' HOUR TO MINUTE
           The time zone 8 hours west from UTC (equivalent to PST).

       LOCAL
       DEFAULT
           Set the time zone to your local time zone (that is, the
           server's default value of timezone).

       Timezone settings given as numbers or intervals are internally
       translated to POSIX timezone syntax. For example, after SET TIME
       ZONE -7, SHOW TIME ZONE would report <-07>+07.

       See Section 8.5.3, "Time Zones", in the documentation for more
       information about time zones.

NOTES

   The function set_config provides equivalent functionality; see Section
   9.26, "System Administration Functions", in the documentation. Also, it
   is possible to UPDATE the pg_settings system view to perform the
   equivalent of SET.

EXAMPLES

   Set the schema search path:

       SET search_path TO my_schema, public;

   Set the style of date to traditional POSTGRES with "day before month"
   input convention:

       SET datestyle TO postgres, dmy;

   Set the time zone for Berkeley, California:

       SET TIME ZONE 'PST8PDT';

   Set the time zone for Italy:

       SET TIME ZONE 'Europe/Rome';

COMPATIBILITY

   SET TIME ZONE extends syntax defined in the SQL standard. The standard
   allows only numeric time zone offsets while PostgreSQL allows more
   flexible time-zone specifications. All other SET features are
   PostgreSQL extensions.

SEE ALSO

   RESET(7), SHOW(7)

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