NT compression on datafiles

From: Michael Keppler <Michael.Keppler_at_bigfoot.com>
Date: Thu, 16 Dec 1999 11:52:47 +0100
Message-ID: <83ag16$deh@TGZ3>

Hello everybody !

We have Oracle 8 running on NT. So I tried what happens if I use NT file compression on datafiles. Some of my tablespaces could be compressed up to a factor of 8. My question is: How does file compression affect database performance ?

What I think is the following:
If I make some very selective query, I only read some data from disk and it may be slower with compression. On the other side, if I have to get some thousand rows out of some tables I have to read some MB of data. And I believe this could be faster with compressed files because I have to read only 10 MB instead of 80 MB on my disks and I think the process of NT file decompression is very fast.

If I change my data very often, NT has to run the process of compression every time a block is written to disk. This could affect performance very much.

So I think I could use file compression on data that is actually read very often but nearly never changed.

Does anyone have some comments or maybe proofen facts about this ?

Ciao and Thanks, Michael.

--
Michael Keppler, MCSE, MCP+I
IT logic GbR
Michael.Keppler_at_gmx.de
--> verteilte Klimasimulation http://www.climate-dynamics.rl.ac.uk
Received on Thu Dec 16 1999 - 04:52:47 CST