pt-online-schema-change doesn't work with PXC and MyISAM tables

[Daniel Nichter]

This is due to bug 1064057, bug 1080913, and bug 1081364. If or when those bugs are fixed upstream, we'll un-target them from 2.2.1 and just keep this "covering bug".

[Daniel Nichter (daniel-nichter)]

For the moment, pt-osc refuses to work on MyISAM tables; it will detect and die with an error. There are too many issues with PXC and MyISAM to make this safe.

[Daniel Nichter (daniel-nichter)]

Chance are this will never work. MyISAM support for PXC isn't a priority afaik. Even if it were, it would still be risky for pt-osc (very difficult to say how non-transactional stuff works in a semi-sync cluster with 3 tables, 3 triggers, other writers, etc.). We've already noted in the pt-osc docs that,

"""
pt-online-schema-change works with Percona XtraDB Cluster (PXC) 5.5.28-23.7
and newer, but there are two limitations: only InnoDB tables can be altered,
and C<wsrep_OSU_method> must be set to C<TOI> (total order isolation).
"""

So I'm just going to say that this is now "policy" and close this bug.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-1050