Hello, If you don't query against Wikidata database and specially wb_items_per_site, please ignore this message.

We recently dropped wb_entity_per_page table and as result some queries had to change, namely the ones that querying against wb_terms and wb_items_per_site tables because these two store the entity numeric id instead of full id (e.g. Q7251 vs. 7251) so when you join against these tables you need to add concatenation, for example CONCAT("Q", ips_item_id).

This sometimes can have performance implications and force you to rewrite the whole query in order to obtain desired performance which is not true in wb_terms table anymore because it now contains both numeric id (term_entity_id) and the full id (term_full_entity_id). But we haven't done it for wb_items_per_site table yet.

So the question is, are querying against this table and does using concatenation caused you performance problems? If your answer is yes, please raise your voice in phabricator [0]

[0]: https://phabricator.wikimedia.org/T179928

Best