Re: BUG #2342: Extremely bad performance on a specific query, compared to 7.4

"Mattias Kregert" <mattias@kregert.se> writes:
> SELECT id FROM pics WHERE
> (file='3a76h3gd873kmn7ckd76' AND archived IS NULL) OR
> (file='jj38kmc983lmn2547cx0' AND archived IS NULL) OR
> ...

Could we see EXPLAIN ANALYZE results for this query from both the 7.4
and 8.1 systems?  Since you haven't even told us what indexes are
available on the table, there's not a lot we can do with this report.

            regards, tom lane