The Cognate extension requires an additional database to be created with tables that will be shared between all wiktionaries.
The extension is already running on beta, a database named cognate_wiktionary has been created on the extension1 cluster.
I imagine it would make sense to carry this over into production (as long as the DBA team approve)
The extension is scheduled for deployment on the 24th April (see parent ticket).
1 Database must be created on the decided cluster named 'cognate_wiktionary'
3 Tables must be created, SQL can be found @ https://phabricator.wikimedia.org/diffusion/1890/browse/master/db/