At least four unsuccessful bugfixes in MySQL 5.0.23

MySQL 5.0.23 will not be officially released due to the fix for bug #10952 (an ALTER TABLE to MERGE or BLACKHOLE should have been forbidden to prevent the loss of data in the table). The fix introduced some unwanted side effects and needs to be reverted in the upcoming release 5.0.24. But this was not the only bugfix with negative side effects in 5.0.23: I tried the build today and just discovered three other bugfixes introducing new bugs while actually trying to fix old ones.

Just a few days ago Baron Schwartz wrote an article on how to replace large IN clauses with a UNION SELECT as a subquery in a JOIN (Why large IN clauses are problematic). Unfortunately this trick will not work anymore in MySQL 5.0.23, at least when you haven't selected a default database previously. As we used similar approaches in our code, bug #21002 introduced in 5.0.23 is breaking some of our applications that were running fine since early 4.1 releases of MySQL.

The same is true for bug #20989: In 5.0.23 some cross-schema INSERT/REPLACE statements selecting from a VIEW with an SQL SECURITY of the INVOKER suddenly stop to work, even when the user executing the query has all the rights necessary to access the VIEW.

There were (and are) some problems with VIEW rights, cross-schema queries and the default database in MySQL. Some work has been done on that in 5.0.23. But it seems that the bugs have just been shifted to other places.

This doesn't happen only with the server, but also on the client side: Markus Popp just blogged happily about mysqldump improvements and mentioned the corrected dump of view structures. But instead of just dumping views incorrectly, mysqldump in 5.0.23 now crashes with a segmentation fault on certain views (bug #21014).

I really hope 5.0.24 will not only revert the first mentioned bugfix but also correct these (and possibly other) unsuccessful bugfixes. You should help the developers and QA by downloading 5.0.23 (even if it hasn't been released officially you can get it from the download servers by just changing the URL) and checking it against your existing applications that are working fine with 5.0.22. I think all the people using MySQL 5 in production really need a bugfix release finally that doesn't break existing features. There would've been so many important improvements in release 5.0.23 of MySQL...