Re: remove spurious CREATE INDEX CONCURRENTLY wait

James Coleman  writes:
> Why is a CIC in active index-building something we need to wait for?
> Wouldn't it fall under a similar kind of logic to the other snapshot
> types we can explicitly ignore? CIC can't be run in a manual
> transaction, so the snapshot it holds won't be used to perform
> arbitrary operations (i.e., the reason why a manual ANALYZE can't be
> ignored).

Expression indexes that call user-defined functions seem like a
pretty serious risk factor for that argument.  Those are exactly
the same expressions that ANALYZE will evaluate, as a result of
which we judge it unsafe to ignore.  Why would CIC be different?

			regards, tom lane