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Message-ID: <4C5837C0.6060704@gmail.com>
Date: Tue, 03 Aug 2010 17:37:36 +0200
From: Yeb Havinga <yebhavinga@gmail.com>
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To: Hannu Krosing <hannu@2ndquadrant.com>
CC: Scott Marlowe <scott.marlowe@gmail.com>,
	Greg Smith <greg@2ndquadrant.com>,
	Josh Berkus <josh@agliodbs.com>, pgsql-performance@postgresql.org
Subject: Re: Testing Sandforce SSD
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Yeb Havinga wrote:
> Hannu Krosing wrote:
>> Did it fit in shared_buffers, or system cache ?
>>   
> Database was ~5GB, server has 16GB, shared buffers was set to 1920MB.
>> I first noticed this several years ago, when doing a COPY to a large
>> table with indexes took noticably longer (2-3 times longer) when the
>> indexes were in system cache than when they were in shared_buffers.
>>   
> I read this as a hint: try increasing shared_buffers. I'll redo the 
> pgbench run with increased shared_buffers.
Shared buffers raised from 1920MB to 3520MB:

 pgbench -v -l -c 20 -M prepared -T 1800 test
starting vacuum...end.
starting vacuum pgbench_accounts...end.
transaction type: TPC-B (sort of)
scaling factor: 300
query mode: prepared
number of clients: 20
duration: 1800 s
number of transactions actually processed: 12971714
tps = 7206.244065 (including connections establishing)
tps = 7206.349947 (excluding connections establishing)

:-)