suse man page for discard

DISCARD(7)							   SQL Commands 							DISCARD(7)

NAME
       DISCARD - discard session state

SYNOPSIS
       DISCARD { ALL | PLANS | TEMPORARY | TEMP }

DESCRIPTION
       DISCARD releases internal resources associated with a database session. These resources are normally released at the end of the session.

       DISCARD	TEMP  drops all temporary tables created in the current session. DISCARD PLANS releases all internally cached query plans. DISCARD
       ALL resets a session to its original state, discarding temporary resources and resetting session-local configuration changes.

PARAMETERS
       TEMPORARY or TEMP
	      Drops all temporary tables created in the current session.

       PLANS  Releases all cached query plans.

       ALL    Releases all temporary resources associated with the current session and resets the session to its initial state.   Currently,  this
	      has the same effect as executing the following sequence of statements:

	      SET SESSION AUTHORIZATION DEFAULT;
	      RESET ALL;
	      DEALLOCATE ALL;
	      CLOSE ALL;
	      UNLISTEN *;
	      SELECT pg_advisory_unlock_all();
	      DISCARD PLANS;
	      DISCARD TEMP;

NOTES
       DISCARD ALL cannot be executed inside a transaction block.

COMPATIBILITY
       DISCARD is a PostgreSQL extension.

SQL - Language Statements					    2010-05-14								DISCARD(7)