[PERFORM] Question about network bandwidth usage between PostgreSQL’s client and server

2013-04-24 Thread Kelphet Xiong
88% of that of partsupp, why the average network usage for sequential scan of lineitem table is only 50% that of partsupp table? And why the average network usage of their join is higher than that of sequential scan of lineitem but lower than that of sequential scan of partsupp table? Thanks! Kelphet Xiong

Re: [PERFORM] Question about postmaster's CPU usage

2013-03-30 Thread Kelphet Xiong
ect * from inventory; ERROR: syntax error at or near "analyze" LINE 1: explain (analyze on, timing off) select * from inventory; ^ Thanks! Best regards Kelphet Xiong On Thu, Mar 28, 2013 at 2:03 PM, Kevin Grittner wrote: > kelphet xiong wrote: > > > When I

[PERFORM] Question about postmaster's CPU usage

2013-03-28 Thread kelphet xiong
Hi all, When I use postgres and issue a simple sequential scan for a table inventory using query "select * from inventory;", I can see from "top" that postmaster is using 100% CPU, which limits the query execution time. My question is that, why CPU is the bottleneck here and what is postmaster