Topic on Project:Support desk

Hello!

Just to be sure about: Older MediaWiki installations (1.11, 1.15) show almost just MyISAM tables though InnoDB is always set in the LocalSettings.php; 1.19 installations show mixed, though MyISAM dominates (and InnoDB set in the LocalSettings.php); in contrary 1.22 shows just InnoDB tables. (All on MySQL, 5.0/5.1.)

So I think though InnoDB was always set MediaWiki used basically MyISAM tables, but changed this behaviour through the versions in direction to InnoDB. Is this right? (Did not find anything regarding this in the HISTORY files.)

Best regards

Jörg

Hi Jörg,

yes, this is right. At some point InnoDB became available in MySQL and when more and more users had versions with InnoDB support, MediaWiki changed to using InnoDB as default table engine. MediaWiki comes with the maintenance/tables.sql file, which contains the database setup (tables and so). For nearly all tables, this file contains /*$wgDBTableOptions*/ as some kind of "marker"; then MediaWiki will create the table with the engine defined in $wgDBTableOptions - by default with InnoDB. But there still are very few tables (definitely the table searchindex, maybe also one or two others), which do not use InnoDB, but MyISAM; in this case such a marker is not present in the sql file. Instead, MyISAM is defined as table engine.

If you upgrade a wiki to a newer version of MediaWiki and if you want to use the advantages of InnoDB also for that old installation, you can also manually change the engine type of your tables to InnoDB!