MySQL 8 Cookbook

Using EXPLAIN

The EXPLAIN plan shows all the partitions scanned for a query. If you run the EXPLAIN plan for SELECT * FROM <table>, it lists all the partitions, for example:

mysql> EXPLAIN SELECT * FROM employees\G*************************** 1. row ***************************           id: 1  select_type: SIMPLE        table: employees   partitions: p1980,p1990,p2000,p2010,p2020,pmax         type: ALLpossible_keys: NULL          key: NULL      key_len: NULL          ref: NULL         rows: 292695     filtered: 100.00        Extra: NULL1 row in set, 1 warning (0.00 sec)