(was "Database used by wikidata")
We would LOVE for more developers or systems administrators to help
support MediaWiki core on other RDBMSes; one of the most helpful things
you can do is help look at the changes other developers are making that
might affect your preferred RDBMS, and provide testing and code review.
https://www.mediawiki.org/wiki/Code_review_guide
For instance, here's a search for not-yet-merged commits that mention
PostgreSQL in their commit summaries:
https://gerrit.wikimedia.org/r/#/q/message:postg,n,z
Anyone can comment on those code changes in Gerrit by getting "developer
access" which you can get instantly. See
https://www.mediawiki.org/wiki/Developer_access .
Please see
https://www.mediawiki.org/wiki/Database_testing for lists of
things to test, and feel free to add to "Creating a test plan for
databases".
As Aude pointed out, there is at least one db in the WMF cluster now
running MariaDB. More details:
http://lists.wikimedia.org/pipermail/wikitech-l/2012-December/064994.html
--
Sumana Harihareswara
Engineering Community Manager
Wikimedia Foundation