From: "Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>
To: pgsql-performance@postgresql.org
Date: Mon, 18 Aug 2003 21:32:27 +0530
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Subject: Re: Insert performance
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On 18 Aug 2003 at 18:52, Hannu Krosing wrote:
> My own experimentation also got numbers in 9k/sec range (on a quad
> 1.3GHz Xeons, 2GM mem, 50MB/sec raid) when doing 10-20 parallel runs of
> ~1000 inserts/transaction.
> 
> Performance dropped to ~300/sec (at about 60M rows) when I added an
> index (primary key) - as I did random inserts, the hit rates for index
> pages were probably low.

I was loading a geographic data couple of months back.. It was 3GB data when 
loaded in postgresql.

I tried loading data first and creating index later. It ran out of available 
9GB space. So I created index on an empty table and started loading it. It was 
slow but at least finished after 3 hours... Co-incidentally oracle had same 
problems as well. So creating index beforehand remains only option at times, it 
seems. Tom remarked that it shouldn't have made difference but apparently it 
does..

You mentioned parallel runs and still getting 9K/sec. Was that overall 9K or 
per connection? If it is former, probably WAL is hit too hard. You could do 
some additional testing by having WALit's own disk.

I was plannning to do the multiple writers test. But since objective was to 
find out why postgresql was so slow and it tunred out to be slowaris in first 
place, didn't have any enthu. left.

I recommended my colleague to move to linux. But apparently this product is a 
part of suit which runs on some HUGE solaris machines. So if it has to run 
postgresql, it has to run sunos. I hope they are faster with SCSI..

Bye
 Shridhar

--
On my planet, to rest is to rest -- to cease using energy.  To me, itis quite 
illogical to run up and down on green grass, using energy,instead of saving it.	
	-- Spock, "Shore Leave", stardate 3025.2