DISCARD — discard session state
DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
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.
PLANSReleases 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 TEMPDrops all temporary tables created in the current session.
ALLReleases 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;
DISCARD ALL cannot be executed inside a transaction block.
DISCARD is a PostgreSQL extension.