…, 0 rows affected (24.84 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> select count(*) from idxitest where a=5 and… original index it will quite likely be unable to use new index to full extent. What is solution ? You can have “redundant” indexes on… be very careful applying index changes from mk-duplicate-key-checker key checker when it comes to redundant indexes. If you have query…