PostgreSQL 7.4beta4 Documentation
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# SET

## 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 Section 16.4 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.

## 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 Section 16.4 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 Section 16.4, 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 (but note some are accepted only on some platforms):

  'PST8PDT'

    The time zone for Berkeley, California.

  'Portugal'

    The time zone for Portugal.

  '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 Section 8.5 for more information about time zones.

## Notes

The function `set_config` provides equivalent functionality. See Section 9.13.

## 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, using quotes to preserve the uppercase spelling of the time zone name:

    SET TIME ZONE 'PST8PDT';
    SELECT current_timestamp AS today;

                 today
    -------------------------------
     2003-04-29 15:02:01.218622-07

## 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, SHOW

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