TRUNCATE() SQL Commands TRUNCATE()NAME
TRUNCATE - empty a table or set of tables
SYNOPSIS
TRUNCATE [ TABLE ] name [, ...] [ CASCADE | RESTRICT ]
DESCRIPTION
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.
PARAMETERS
name The name (optionally schema-qualified) of a table to be trun‐
cated.
CASCADE
Automatically truncate all tables that have foreign-key refer‐
ences to any of the named tables, or to any tables added to the
group due to CASCADE.
RESTRICT
Refuse to truncate if any of the tables have foreign-key refer‐
ences from tables that are not to be truncated. This is the
default.
NOTES
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. The CASCADE option can be used to
automatically include all dependent tables — but be very careful when
using this option, else you might lose data you did not intend to!
TRUNCATE will not run any user-defined ON DELETE triggers that might
exist for the tables.
EXAMPLES
Truncate the tables bigtable and fattable:
TRUNCATE TABLE bigtable, fattable;
Truncate the table othertable, and cascade to any tables that are ref‐
erencing othertable via foreign-key constraints:
TRUNCATE othertable CASCADE;
COMPATIBILITY
There is no TRUNCATE command in the SQL standard.
SQL - Language Statements 2008-06-08 TRUNCATE()
