=?UTF-8?Q?Filip_Rembia=C5=82kowski?= <plk.zuber@xxxxxxxxx> writes: > For the record, I've recently observed such behaviour on non-cheap > 64bit server harware. > That was Pg 8.4.0. hardware specs available on request. > EXPLAIN ANALYZE SELECT was over 2 times slower that SELECT. repeatedly. > Answering an obligatory question: NO virtualization (vmware/xen/other) there. > Question: > Is there anything as normal, accepted level of performance degradation > when using EXPLAIN ANALYZE compared to plain query? You should certainly not expect it to be free, if that's what you mean. 2X penalty on a very cheap plan node (such as a seqscan with no filter) doesn't surprise me much. BTW, it occurs to me that gettimeofday's microsecond resolution doesn't really get the job done anymore for such cheap plan nodes. I wonder if we should be trying to use clock_gettime() where available. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
