DISCARD

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:

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

Notes

DISCARD ALL cannot be executed inside a transaction block.

Compatibility

DISCARD is a PostgreSQL extension.