Yes, I did not do it in one transaction. All 3 machines are configured with the same OS and same version postgres. No kernel tweaking and no postgres tweaking done (except the fsync)... -----Original Message----- From: Scott Marlowe [mailto:smarlowe@xxxxxxxxxxxxxxxxx] Sent: Tuesday, May 08, 2007 5:23 PM To: Orhan Aglagul Cc: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: [PERFORM] On Tue, 2007-05-08 at 17:59, Orhan Aglagul wrote: > Hi Everybody, > > I was trying to see how many inserts per seconds my application could > handle on various machines. > > Those are the machines I used to run my app: > > > > 1) Pentium M 1.7Ghz > > 2) Pentium 4 2.4 Ghz > > 3) DMP Xeon 3Ghz > > > > Sure, I was expecting the dual Zeon to outperform the Pentium M and 4. > But the data showed the opposite. > > So, I wrote a simple program (in C) using the libpq.so.5 which opens a > connection to the database (DB in localhost), > > Creates a Prepared statement for the insert and does a 10,000 insert. > The result did not change. > > > > Only after setting fsync to off in the config file, the amount of time > to insert 10,000 records was acceptable. > > > > Here is the data: > > > > Time for 10000 inserts > > Fsync=on > > Fsync=off > > Pentium M 1.7 > > ~17 sec > > ~6 sec > > Pentium 4 2.4 > > ~13 sec > > ~11 sec > > Dual Xeon > > ~65 sec > > ~1.9 sec > > > > > I read that postgres does have issues with MP Xeon (costly context > switching). But I still think that with fsync=on 65 seconds is > ridiculous. > > > > Can anybody direct me to some improved/acceptable performance with > fsync=on? I'm guessing you didn't do the inserts inside a single transaction, which means that each insert was it's own transaction. Try doing them all in a transaction. I ran this simple php script: <?php $conn = pg_connect("dbname=smarlowe"); pg_query("begin"); for ($i=0;$i<10000;$i++){ $r = rand(1,10000000); pg_query("insert into tenk (i1) values ($r)"); } pq_query("commit"); ?> and it finished in 3.5 seconds on my workstation (nothing special)
