This documentation is for an older version. If you're using the most current version, select the documentation for that version with the version switch in the upper right corner of the online documentation, or by downloading a newer PDF or EPUB file.

B.5.4.6 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.