TRUNCATE — empty a table or set of tables
TRUNCATE [ TABLE ] name
[, ...]
TRUNCATE
quickly removes all rows from a set of
tables. It has the same effect as an unqualified
DELETE
on each table, but since it does not actually
scan the tables it is faster. This is most useful on large tables.
Only the owner of a table may TRUNCATE
it.
TRUNCATE
cannot be used on a table that has foreign-key
references from other tables, unless all such tables are also truncated
in the same command. Checking validity in such cases would require table
scans, and the whole point is not to do one.
TRUNCATE
will not run any user-defined ON
DELETE
triggers that might exist for the tables.