Recently I was dealing with an unexpected issue raised by our Support customer, in which data became inconsistent after a schema change was applied.
After some investigation, it turned out that affected tables had a special word in the comments of some columns, which triggered an already known (and fixed) issue with the TableParser.pm library of Percona Toolkit. The problem is that the customer was using an outdated Toolkit version, where pt-online-schema-change was using that buggy parser.
This bug applies only to Percona Toolkit versions up to 3.0.10, so if you have already 3.0.11 or newer installed, you can skip the rest of this post as these are no longer affected.
I am writing this post to warn every user of pt-online-schema-change who has not upgraded the toolkit, as …[Read more]