Hello, As part of improving performance and stability of the recentchanges table, we are addressing some tech debt. rc_new field was deprecated 13 years ago and rc_type similarly was deprecated 11 years ago. We are moving forward with dropping these columns in favour of rc_source field.

If you're querying rc_new or rc_type, please switch to using rc_source instead. They will be removed from wikireplicas in a week.

This would allow us to consolidate several different indexes on this table and improve performance of Special:Recentchanges and Watchlist plus simplifying MediaWiki code.

To follow the work, you can check https://phabricator.wikimedia.org/T400696 and related subtickets.

Thank you and apologies for the inconvenience Best