B.4.4.6 Deleting Rows from Related Tables
If the total length of the DELETE
statement for related_table
is more than 1MB (the default value of the max_allowed_packet
system variable), you should split it into smaller parts and execute multiple DELETE
statements. You probably get the fastest DELETE
by specifying only 100 to 1,000 related_column
values per statement if the related_column
is indexed. If the related_column
isn't indexed, the speed is independent of the number of arguments in the IN
clause.