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)