In the last exciting episode, [EMAIL PROTECTED] wrote: >> [EMAIL PROTECTED] (Rajesh Kumar Mallah) wrote: >>> Can you please have a Look at the below and suggest why it >>> apparently puts 7.3.4 on an infinite loop . the CPU utilisation of the backend >>> running it >>> approches 99%. >> >> What would be useful, for this case, would be to provide the query plan, perhaps via >> >> EXPLAIN [Big Long Query]. >> >> The difference between that EXPLAIN and what you get on 7.4 might be quite >> interesting. >> >> I would think it quite unlikely that it is truly an "infinite" loop; it is rather >> more likely >> that the plan winds up being pretty bad and doing something [a bunch of nested >> loops, maybe?] >> that run longer than your patience will permit. > > :-) ok i will leave it running and try to get it.
No, if you just do EXPLAIN (and not EXPLAIN ANALYZE), that returns without executing the query. If the query runs for a really long time, then we _know_ that there is something troublesome. EXPLAIN (no ANALYZE) should provide some insight without having anything run for a long time. If EXPLAIN [big long query] turns into what you are terming an "infinite loop," then you have a quite different problem, and it would be very useful to know that. -- "cbbrowne","@","ntlug.org" http://www3.sympatico.ca/cbbrowne/oses.html This is Linux country. On a quiet night, you can hear NT re-boot. ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings