On 22.10.2013 00:59, sparikh wrote: > Yes, Expalin without Analyze is taking long. It is weird. In the > pg_stat_activity Explain was the only query running. So server was > almost idle. Using New relic interface I checked CPU was almost idle > - around 10-20%. There were some IO activity - around 40-50%. > > I forgot to mention before I could run perf on command line even with > root permission. It says command not found. May be utility is not > installed or not enabled. Obviously you need to install it ... maybe ask your sysadmin to do that. > I have attached the snapshot of vmstat while explain was running in > background. vmstat.txt > <http://postgresql.1045698.n5.nabble.com/file/n5775349/vmstat.txt> The vmstat clearly shows that ~1 CPU is waiting on I/O. Hmm, I'm really wondering what's going on here - I can't think of a case where this would happen with a plain EXPLAIN ... We really need the perf results. Or try to run strace, maybe it'll give more info about which files it accesses. > Do you suggest if I remove all the data files from /data/base folder > of standby and again rebuild using rsync from primary ? do you see > any issues there.? This is just to rule out any fragmentation on > standby side. The EXPLAIN really should not do much I/O. I doubt it has anything to do with fragmentation, so I doubt this is going to help. > Our sys admin is planning to run fsck sometime today or tomorrow. OK. Which filesystem do you use, btw? Tomas -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
