set(7)
NAME
SET - change a run-time parameter
SYNOPSIS
SET [ SESSION | LOCAL ] name { 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 the documentation can be changed on-thefly 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 SET SESSION is issued within a transaction that is later
aborted, the effects of the SET command disappear when the transaction
is rolled back. (This behavior represents a change from PostgreSQL versions prior to 7.3, where the effects of SET would not roll back after
a later error.) 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.
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. Note that SET LOCAL will appear to have no effect if it is executed outside a BEGIN block, since the transaction will end immediately.
- name Name of a settable run-time parameter. Available parameters are
- documented in the documentation and below.
- value New value of parameter. Values can be specified as string con
- stants, identifiers, numbers, or comma-separated lists of these. DEFAULT can be used to specify resetting the parameter to its default value.
- Besides the configuration parameters documented in the documentation, there are a few that can only be adjusted using the SET command or that have a special 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 0 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 (the one that the server's operating system defaults to).
- See the documentation for more information about time zones. Also, the documentation has a list of the recognized names for time zones.
NOTES
The function set_config provides equivalent functionality. See the documentation.
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 [reset(7)], SHOW [show(l)]