TRUNCATE

TRUNCATE — empties a table

Syntax

TRUNCATE TABLE [schema.]tableName

Description

TRUNCATE operates on the table instead of individual rows. Therefore the command TRUNCATE TABLE removes all rows from a table without logging individual row deletions. It is more efficient than using DELETE without a WHERE clause for large tables.

The user must have the DELETE privilege on the table in order to invoke TRUNCATE on it. After execution of TRUNCATE TABLE, disk space is not reclaimed immediately. To reclaim new unused disk space, use NuoDB Archive.

When using multiple statements in a single call, the TRUNCATE command can only be used if it is the first statement in the call. If it is not, an error is returned.

For example:

SQL> create table if not exists a (a int); truncate table a;
syntax error on line 1
create table if not exists a (a int); truncate table a;
                                                      ^
expected = got TABLE

Parameters

tableName: Name of the table to be truncated (optionally schema-qualified).

Example

CREATE TABLE tab_truncate (col1 STRING);
INSERT INTO tab_truncate VALUES ('row1'),('row2'),('row3');
SELECT * FROM tab_truncate;
 COL1
 -----
 row1
 row2
 row3

TRUNCATE TABLE tab_truncate;
SELECT * FROM tab_truncate;

/* There are no records selected */