/usr/man2/cat.l/set.l.Z
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-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 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 ver-
sions 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 transac-
tion, 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 trans-
action 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 doc-
umentation.
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 Post-
greSQL extensions.
SEE ALSO
RESET [reset(l)], SHOW [show(l)]
SQL - Language Statements 2005-11-05 SET()
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