DEALLOCATE — deallocate a prepared statement
DEALLOCATE [ PREPARE ] { name | ALL }
DEALLOCATE is used to deallocate a previously prepared SQL statement. If you do not explicitly deallocate a prepared statement, it is deallocated when the session ends.
For more information on prepared statements, see PREPARE.
PREPAREThis key word is ignored.
nameThe name of the prepared statement to deallocate.
ALLDeallocate all prepared statements.
The SQL standard includes a DEALLOCATE statement, but it is only for use in embedded SQL.
Read the upstream documentation. For corrections, first check the current version.