Re: Compress for OLTP

From: Jonathan Lewis <>
Date: Fri, 28 Dec 2012 12:24:49 -0000
Message-ID: <>

"Mladen Gogala" <> wrote in message
| There is a lengthy discussion on oracle-l about "COMPRESS FOR OLTP"
option which costs
| approximately $10k per CPU thread. Being a curious George that I am, I
decided to test.
| Here are two SQL script that I used to test:
| ...
| Oracle's compression algorithm simply isn't very efficient despite the
| fact that the table used is not very good for compression because it's
| generated using random strings which do not repeat themselves.
| --
| Mladen Gogala
| The Oracle Whisperer

Coincidentally I'm writing a short series of articles on table compression for Redgate, so I was tempted to point out on that thread that the reported effects were exactly the sort of thing you'd expect to see.

Oracle doesn't do "compression" for OLTP or BASIC, by the way, it's simply de-duplication with a block. This has all sorts of interesting little side effects, some of which are not what you might expect.


Jonathan Lewis

Author: Oracle Core (Apress 2011)
Received on Fri Dec 28 2012 - 13:24:49 CET

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