The purpose of this page is to collect information and experiences about running MediaWiki on PostgreSQL.
MediaWiki supports PostgreSQL since 1.7, but please note that this is second-class support, and you will likely run into many bugs. The database most commonly used with MediaWiki is MySQL. See Phabricator for a list of issues. MediaWiki requires PostgreSQL 9.2 or later, and PG database support enabled in PHP.
Most of the common maintenance scripts work with PostgreSQL; however, some of the more obscure ones might have problems.
Is PostgreSQL a good choice for MediaWiki?
Wikimedia uses MariaDB so MediaWiki gets more testing on MariaDB than PostgreSQL. While support for PostgreSQL is maintained by volunteers, most core functionality is working.
MediaWiki database migration
The best is to migrate only XML-content and filesystem images. See simple complete terminal steps at https://stackoverflow.com/a/8771896/287948
From MySQL to PostgreSQL
The MWDumper tool might help.
There is also a mediawiki_mysql2postgres.pl perl script in maintenance/postgres, but there is uncertainty whether it works.
From PostgreSQL to MySQL
This is generally not recommended as converting from Postgres data types back to MySQL is not as simple an operation as the reverse.
There are, however, some scripts which may work.