Provided by: postgresql-client-9.5_9.5.25-0ubuntu0.16.04.1_amd64 
NAME
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
(CREATE_SEQUENCE(7)) 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.