SET(5)

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SET(5)
NAME
  SET - change a run-time parameter

SYNOPSIS
  SET variable { TO | = } { value | 'value' | DEFAULT }
  SET TIME ZONE { 'timezone' | LOCAL | DEFAULT }

  INPUTS

  variable
       A settable run-time parameter.

  value
       New value of parameter. DEFAULT can be used to specify resetting the
       parameter to its default value. Lists of strings are allowed, but more
       complex constructs may need to be single or double quoted.

DESCRIPTION
  The SET command changes run-time configuration parameters. The following
  parameters can be altered:

  CLIENT_ENCODING

  NAMES
       Sets the multibyte client encoding. The specified encoding must be
       supported by the backend.

       This option is only available if PostgreSQL is build with multibyte
       support.

  DATESTYLE
       Choose the date/time representation style. Two separate settings are
       made: the default date/time output and the interpretation of ambiguous
       input.

       The following are date/time output styles:

       ISO
	 Use ISO 8601-style dates and times (YYYY-MM-DD HH:MM:SS). This is
	 the default.

       SQL
	 Use Oracle/Ingres-style dates and times. Note that this style has
	 nothing to do with SQL (which mandates ISO 8601 style), the naming
	 of this option is a historical accident.

       PostgreSQL
	 Use traditional PostgreSQL format.

       German
	 Use dd.mm.yyyy for numeric date representations.

  The following two options determine both a substyle of the ``SQL'' and
  ``PostgreSQL'' output formats and the preferred interpretation of ambiguous
  date input.

       European
	 Use dd/mm/yyyy for numeric date representations.

       NonEuropean

       US
	 Use mm/dd/yyyy for numeric date representations.

  A value for SET DATESTYLE can be one from the first list (output styles),
  or one from the second list (substyles), or one from each separated by a
  comma.

  Date format initialization may be done by:

  Setting the PGDATESTYLE environment variable.	 If PGDATESTYLE is set in the
  frontend environment of a client based on libpq, libpq will automatically
  set DATESTYLE to the value of PGDATESTYLE during connection start-up.

  Running postmaster using the option -o -e to set dates to the European
  convention.

  The DateStyle option is really only intended for porting applications. To
  format your date/time values to choice, use the to_char family of
  functions.

  SEED Sets the internal seed for the random number generator.

       value
	 The value for the seed to be used by the random function. Allowed
	 values are floating-point numbers between 0 and 1, which are then
	 multiplied by 231-1. This product will silently overflow if a number
	 outside the range is used.

	 The seed can also be set by invoking the setseed SQL function:

	 SELECT setseed(value);

  SERVER_ENCODING
       Sets the multibyte server encoding.

       This option is only available if PostgreSQL was built with multibyte
       support.

  TIME ZONE

  TIMEZONE
       Sets the default time zone for your session. Arguments can be an SQL
       time interval constant, an integer or double precision constant, or a
       string representing a time zone supported by the host operating
       system.

       The possible values for time zone depends on your operating system.
       For example, on Linux /usr/share/zoneinfo contains the database of
       time zones.

       Here are some valid values for time zone:

       'PST8PDT'
	 Set the time zone for California.

       'Portugal'
	 Set the time zone for Portugal.

       'Europe/Rome'
	 Set the time zone for Italy.

       7 Set the time zone to 7 hours offset west from GMT (equivalent to
	 PDT).

       INTERVAL '08:00' HOUR TO MINUTE
	 Set the time zone to 8 hours offset west from GMT (equivalent to
	 PST).

       LOCAL

       DEFAULT
	 Set the time zone to your local time zone (the one that your
	 operating system defaults to).

  If an invalid time zone is specified, the time zone becomes GMT (on most
  systems anyway).

  If the PGTZ environment variable is set in the frontend environment of a
  client based on libpq, libpq will automatically set TIMEZONE to the value
  of PGTZ during connection start-up.

  An extended list of other run-time parameters can be found in the
  Administrator's Guide.

  Use SHOW [show(5)] to show the current setting of a parameters.

DIAGNOSTICS
  SET VARIABLE
       Message returned if successful.

  ERROR: not a valid option name: name
       The parameter you tried to set does not exist.

  ERROR: permission denied
       You must be a superuser to have access to certain settings.

  ERROR: name can only be set at start-up
       Some parameters are fixed once the server is started.

EXAMPLES
  Set the style of date to traditional PostgreSQL with European conventions:

  SET DATESTYLE TO PostgreSQL,European;

  Set the time zone for Berkeley, California, using double quotes to preserve
  the uppercase attributes of the time zone specifier (note that the
  date/time format is ISO here):

  SET TIME ZONE "PST8PDT";
  SELECT CURRENT_TIMESTAMP AS today;

	   today
  ------------------------
   1998-03-31 07:41:21-08

  Set the time zone for Italy (note the required single or double quotes to
  handle the special characters):

  SET TIME ZONE 'Europe/Rome';
  SELECT CURRENT_TIMESTAMP AS today;

	   today
  ------------------------
   1998-03-31 17:41:31+02

COMPATIBILITY
  SQL92

  The second syntax shown above (SET TIME ZONE) attempts to mimic SQL92.
  However, SQL allows only numeric time zone offsets. All other parameter
  settings as well as the first syntax shown above are a PostgreSQL
  extension.
Index for
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