Hi, I really appreciate the great database schema, but it seems to me that some of the tables are not public. For example, it looks like watchlist information is not public, I assume to prevent vandalism. Is there a version of the schema that includes info about what tables are public-facing, or am I confused about the tables in some way? Thank you! Otherwise, looks like I can use any table returned by SHOW tables;
Topic on Talk:Quarry
You should indeed be able to use anything that show tables; lists.
The best documentation of how the Wiki Replicas differ from the raw operational schema of the production wikis is found at https://wikitech.wikimedia.org/wiki/Help:Toolforge/Database#Replica_database_schema_(tables_and_indexes).
The watchlist table specifically is hidden from the Wiki Replica databases because details of who is watching which page are not public on the wikis. A logged in user can only see their own watchlist and anonymous users cannot see any watchlists at all.
There is an open ticket about restoring a derived table that once existed on the Wiki Replicas that would expose aggregate counts how many people are watching a given page. This information is currently available via the Action API using api.php?action=query&prop=info&inprop=watchers&titles=.... That ticket is currently stalled on the DBA and Cloud Services teams finding a reliable way to manage derived tables across the Wiki Replica fleet.
Thank you, Bryan! Will be interesting to see if that derived table ever goes live. In addition to the technical challenges, I wonder about the risks of exposing low-count pages in namespace 0 to potential vandals.