Edit to spec as necessary:
DELIMITER $$ CREATE PROCEDURE trimTable() BEGIN DECLARE ROWS INT; DECLARE rows_deleted INT; SET ROWS = 1; SET rows_deleted = 10000; WHILE ROWS > 0 DO DELETE FROM db.tabA WHERE predicate_col < CURDATE() - INTERVAL 90 DAY ORDER BY `id` LIMIT 10000; SET ROWS = ROW_COUNT(); SET rows_deleted = rows_deleted + ROW_COUNT(); SELECT rows_deleted AS "Rows Deleted"; END WHILE; END $$ DELIMITER ;