Re: Help: System requirements for postgresql 7.4.1

Hi,

In fact it is difficult to answer to that questions as they depend of how big is your database, how many simultaneous connections you
have, ... etc
But, I can help you by giving you my results on a Bi-CPU Xeon 2.6 GHz , 4 Gb RAM, external 2 x RAID0 on four disks each with Redhat
9.0.

1) Connections : This system support easily 500 simultaneous connections. The performances decrease only by 11 % between 100 users and
500 users.

2) Database size : This is a bit more complex. If your database size is 700 Mb (less << RAM size) the performances are very good. But
when the database size is bigger than the RAM size, the I/O increased rapidly and your system spend time in Wait I/O state. For
example, I have noted that from 700 Mb to 7 Gb the performances drop by 65% on my 4 GB memory machine. That' s don't means they are
bad but that means that if you want to improve performances on very big Database you should have to spend money to increase the I/O
throughput instead of bought more CPUs.
Please note that this remarks is valid on other RDBMS, even on commercial RDBMS.
Please note too, that there is about 30 % of performance gain between SCSI internal disks and an external RAID0 Chaparral LUN.

About the software, I have preferred to install my own downloaded Postgres 7.4 version as the Database Redhat package is a less recent
Postgres version (7.2 or 7.3) and a lot of things have been improved in the 7.4. Further more, I prefer to install all Postgres bin
and lib in /usr/local/pgsql than in /usr/bin and /usr/lib.

Thierry Missimilly

Juan Carlos Diez wrote:

> Hello, I'm evaluating that version and I can't find system requirements for it. Could anybody please help me with these questions?
>
> 1.1. Hardware:
> 1.1.1. C.P.U. (how many processors, what speed)
> 1.1.2. Ram. (minimum and desired)
> 1.1.3. Disk.
> 1.1.4. Networking.
> 1.1.5. Scalability
>
> 1.2. Software:
> 1.2.1. OS. (wich versions and patches are required for linux and solaris)
> 1.2.2. Required software packages.
>
> Thank you very much.
>
> Best regards,
>
> JCD.
>
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