DISCARD

DISCARD — discard session state

Synopsis

DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }

Description

DISCARD releases internal resources associated with a database session. This command is useful for partially or fully resetting the session's state. There are several subcommands to release different types of resources; the DISCARD ALL variant subsumes all the others, and also resets additional state.

Parameters

  • PLANS

    • Releases all cached query plans, forcing re-planning to occur the next time the associated prepared statement is used.
  • SEQUENCES

    • Discards all cached sequence-related state, including currval() / lastval() information and any preallocated sequence values that have not yet been returned by nextval() . (See CREATE SEQUENCE for a description of preallocated sequence values.)
  • TEMPORARY or TEMP

    • Drops all temporary tables created in the current session.
  • 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 SEQUENCES;
DISCARD TEMP;

Notes

DISCARD ALL cannot be executed inside a transaction block.

Compatibility

DISCARD is a PostgreSQL extension.