It can be because of catalog stats file leak. I had it on some older PostgreSQL version when tests were rolling back schema changes often. The file grew to some enormous size and as soon as it got out of cache - it would be very slow to access catalog. I had just to kill the file.
Best regards, Vitalii Tymchyshyn
I am running Postgresql on a Windows Server 2008 server. I have noticed that queries have very high planning times now and then. Planning times go down for the same query immediately after the query runs the first time, but then go up again after if the query is not re-run for 5 minutes or so.
I am not able to find any specific information in the documentation that would explain the issue or explains how to address it, so am asking for advice here.
Here is an example.
explain analyze
select * from message
limit 1
"Limit (cost=0.00..0.44 rows=1 width=1517) (actual time=0.009..0.009 rows=1 loops=1)"
" -> Seq Scan on message (cost=0.00..28205.48 rows=64448 width=1517) (actual time=0.007..0.007 rows=1 loops=1)"
"Planning time: 3667.361 ms"
"Execution time: 1.652 ms"
As you can see the query is simple and does not justify 3 seconds of planning time. It would appear that there is an issue with my configuration but I am not able to find anything that looks out of sorts in the query planning configuration variables. Any advice about what I should be looking for to fix this would be appreciated.
