mariadb mioux@xxx:Prisme> explain SELECT count(*) -> FROM `pdc_client` -> WHERE partenaire in(19765,19764) -> AND `cgp` = 11241 -> LIMIT 50 -> ; +------+---------------+------------+------------+-----------------+----------------+-----------+-------+------------+---------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | |------+---------------+------------+------------+-----------------+----------------+-----------+-------+------------+---------------------------------| | 1 | SIMPLE | pdc_client | ref|filter | cgp,partenaire | cgp|partenaire | 4|4 | const | 21422 (0%) | Using where; Using rowid filter | +------+---------------+------------+------------+-----------------+----------------+-----------+-------+------------+---------------------------------+