Re: Compression

From: joel garry <>
Date: Tue, 15 Dec 2009 08:43:59 -0800 (PST)
Message-ID: <>

On Dec 15, 2:13 am, gazzag <> wrote:
> On 14 Dec, 19:41, Mladen Gogala <> wrote:
> > The word "compression" is very fashionable these days. I find that
> > strange because everybody keeps telling me how cheap disks are these days
> > and yet, there is a slew of compression algorithms all around: MP3,
> > MPEG-2,OGG, ZIP, BZIP2, GZIP, everything is compressed to save the
> > inexpensive and cheap disk space. Oracle seems to have noticed the
> > fashion so they have released a package which should produce the 11.2
> > behavior. The package is called "Oracle Advanced Compression Advisor" and
> > is described here:
> >
> > compression-advisor.html
> > Has anybody played with that? Is there any possibility of compressing the
> > table for OLTP or ("ALL OPERATIONS" in 11.1) in Oracle 10g?
> > I thought of compressing this message to make it more in and fashionable,
> > but the unfortunate effect would be that the message would be somewhat
> > less readable. This message will, however, self-destruct in 5 minutes
> > after reading.
> > --
> I don't believe that compression is simply about saving "cheap" disk
> space as it used to be.  Now that CPUs are so much more powerful, data
> can be uncompressed very quickly in memory reducing disk I/O.
> -g

Or, cpu queues could lengthen, slowing down latch processing, slowing down SGA operations, slowing down I/O requests, increasing cpu queues...

On my machine, there are a few misbehaving reports that are known to peg a cpu (sometimes thrashing SGA, sometimes in-app memory thrashing). When there is just one, not really a problem. When there are several, sometimes a problem. I wouldn't want to add more cpu load when there is a problem, that would make a real problem. The root problem is management wanting up to the minute DSS reports on an OLTP system. Any db is going to have to deal with that. Isn't the direction of Oracle to put everything into a big db for all purposes?


-- is bogus.
Received on Tue Dec 15 2009 - 10:43:59 CST

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