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From: Thomas Kellerer <spam_eater@gmx.net>
To: pgsql-performance@postgresql.org
Subject: Re: Could synchronous streaming replication really degrade the performance of the primary?
Date: Thu, 10 May 2012 14:10:48 +0200
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MauMau, 10.05.2012 13:34:
> Today, they told me that they ran the test on two virtual machines on
> a single physical machine.

Which means that both databases shared the same I/O system (harddisks).
Thererfor it's not really surprising that the overall performance goes down if you increase the I/O load.

A more realistic test (at least in my opinion) would have been to have two separate computers with two separate I/O systems

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