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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 truncated.

  CASCADE
       Automatically truncate all tables that have foreign-key references 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 references
       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
  referencing othertable via foreign-key constraints:

  TRUNCATE othertable CASCADE;


COMPATIBILITY

  There is no TRUNCATE command in the SQL standard.

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