The 'searchindex' table uses MyISAM because until recently, InnoDB did not support fulltext indexes, which MediaWiki uses for the search. All other tables should use InnoDB. According to https://stackoverflow.com/a/9397060 fulltext indexes are available on InnoDB since MySQL 5.6.4. If you're running that version or newer, it is possible you could use InnoDB for that table, but as far as I know no one has tried it before. According to https://www.mediawiki.org/wiki/Compatibility#Database MediaWiki only requires MySQL 5.5.8, so we can't change that in our table definitions (yet). No idea about the 'math' table. -- Bartosz Dziewoński