I can vote for tag synonyms, but I don't have a single post in that tag

Question

The tag synonym list on Stack Overflow offers udf as one of the tags I can vote synonyms to.

Well, I did have one post in that tag, but since 20 days ago I have none (the tag had been misapplied to that one question; note that it hadn't been present in the original revision either).

It looks like the tag creation privilege verification is either using long-obsolete information or not tidying up properly.

The tag synonym FAQ isn't clear on what the rules are, but I'm pretty sure “users who have had enough upvotes in that tag at some point” isn't desirable. I'd expect “users who currently have enough upvotes in that tag” (with perhaps some caching, but not that long).

Answer 1

That would be cause I had a rather silly bug.

-- remove additional
delete ut 
from UserTagTotals ut 
left join #temp t on t.TagId = ut.TagId and t.UserId = ut.UserId 
where ut.Id is null

Should have been...

-- remove additional
delete ut 
from UserTagTotals ut 
left join #temp t on t.TagId = ut.TagId and t.UserId = ut.UserId 
where t.TagId is null

300,000 rows were just successfully deleted.

This was a caching only issue. We build a cache daily for the various top user pages, and also happen to use it for the vote check.