SET — change a run-time parameter
SET [ SESSION | LOCAL ]name{ TO | = } {value| 'value' | DEFAULT } SET [ SESSION | LOCAL ] TIME ZONE {timezone| LOCAL | DEFAULT }
The SET command changes run-time configuration
parameters. Many of the run-time parameters listed in
Chapter 17, Server Configuration 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 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.
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.
nameName of a settable run-time parameter. Available parameters are documented in Chapter 17, Server Configuration and below.
value New value of parameter. Values can be specified as string
constants, 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 Chapter 17, Server Configuration, there are a few that can only be
adjusted using the SET command or that have a
special syntax:
NAMES SET NAMES is an alias for
valueSET 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 is an alias
for valueSET timezone TO . The
syntax valueSET 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.
-7The time zone 7 hours west from UTC (equivalent to PDT). Positive values are east from UTC.
INTERVAL '-08:00' HOUR TO MINUTEThe time zone 8 hours west from UTC (equivalent to PST).
LOCALDEFAULT
Set the time zone to your local time zone (the one that the server's operating system defaults to).
See Section 8.5, “Date/Time Types” for more information about time zones. Also, Appendix B, Date/Time Support has a list of the recognized names for time zones.
The function set_config provides equivalent
functionality. See Section 9.20, “System Administration Functions”.
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';