Run pt-online-schema-change with multiple ALTER queries synchronously

Question

I want to run 3 ALTER queries with pt-online-schema-change tool:

--alter "ADD INDEX userid_sid_ts_fid (user_id, scorecard_id, timestamp, factor_id), DROP INDEX uidts, RENAME INDEX userid_sid_ts_fid to uidts"

However I face this error:

Error altering new table `*****`.`_scoring_basis_new`: DBD::mysql::db do failed: Key 'userid_sid_ts_fid' doesn't exist in table '_scoring_basis_new'

So it looks like is trying to run these 3 queries asynchronously rather than 1 by 1. How can I prevent that?

Answer 1

Try doing that like this

--alter "DROP INDEX uidts,ADD INDEX uidts (user_id, scorecard_id, timestamp, factor_id)"

This should work because I have seen pt-duplicate-key-checker present ALTER TABLE commands dropping a single column out of an index by dropping and redefining like that.

To verify this, make an empty copy of the table and run

CREATE TABLE mycopyoftable LIKE mytable;
ALTER TABLE mycopyoftable
    DROP INDEX uidts
   ,ADD INDEX uidts (user_id, scorecard_id, timestamp, factor_id)
;
SHOW CREATE TABLE mycopyoftable \G