Checksum table syntax-MySql database

Source: Internet
Author: User
CHECKSUM TABLETbl_name[,Tbl_name]... [QUICK | EXTENDED]

Report a table checksum.

If QUICK is specified, the active table checksum is reported. Otherwise, NULL is reported. This is very fast. The active table is enabled by specifying the CHECKSUM = 1 Table option. Currently, it can only be used for MyISAM tables. See section 13.1.5 "create table Syntax ".

In EXTENDED mode, the entire table is read by one row and the checksum is calculated. For large tables, this is very slow.

By default, if neither QUICK nor EXTENDED is specified, and if Table storage engine supports it, MySQL returns an active checksum. Otherwise, the table is scanned.

Checksum table returns NULL for a TABLE that does not exist. In this case, a warning is generated.

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