Thread:Project:Support desk/Moving to MSSQL/reply (2)

Honestly, I would say: You have to install MySQL. While MediaWiki should theoretically support MSSQL, this support compared to MySQL is way less mature. You should expect a variety of things to be not working or having bad performance, just because not so many people use MediaWiki with MSSQL and because it's optimized for MySQL, likely with InnoDB tables in mind.

So, if you want to solve this issue properly, use MySQL. This is the real fix.