BUG #6311: Performance degradation after upgrade

The following bug has been logged online:

Bug reference: 6311
Logged by: Roye Cohen
Email address: roye(dot)cohen(at)sap(dot)com
PostgreSQL version: 9.1.1
Operating system: Linux Redhat
Description: Performance degradation after upgrade
Details:

Hi,

I am a performance engineer. I was conducting a comparison from postgres 9.0
to 9.1.1 in order to upgrade to the newest version.
I found a degradation in physical memory used on DB server (~200%
degradation) and a small degradation in response times on every transaction
monitored in comparison to 9.0.

The test was done on HP LoadRunner with 300 concurrent users executing a
flow of events.

•The exact sequence of steps is hard to describe but it is important to
state that the executions were exactly the same. Default postgres settings
were used (settings were not changed after installing postgres).

OS Version: Linux 2.6.18-164.el5 x86_64

I am at your service if you have any further inqueries.

Best regards,

Roye