RE: Table compression

From: Paul Drake <discgolfdba_at_yahoo.com>
Date: Sat, 20 Mar 2004 21:03:45 -0800 (PST)
Message-ID: <20040321050345.5769.qmail@web20412.mail.yahoo.com>

Jared.Still_at_radisys.com wrote:
> Index compression can lead to buffer busy waits on
> heavily updated
> indexes.
>
> Jared

buffer busy waits can lead to fear and hate. hate leads to the dark side.
slippery slope - beware.

tanel is in for a big heap of trouble in nyc 2nite.

>
>
>
>
>
> "Goulet, Dick" <DGoulet_at_vicr.com>
> Sent by: oracle-l-bounce_at_freelists.org
> 03/19/2004 02:39 PM
> Please respond to oracle-l
>
>
> To: <oracle-l_at_freelists.org>
> cc:
> Subject: RE: Table compression
>
>
> Humm, that's interesting. Anyone have good commenst
> to make about index
> compression??
>
> Dick Goulet
> Senior Oracle DBA
> Oracle Certified 8i DBA
>
> -----Original Message-----
> From: Khedr, Waleed [mailto:Waleed.Khedr_at_FMR.COM]
> Sent: Friday, March 19, 2004 4:05 PM
> To: 'oracle-l_at_freelists.org'
> Subject: RE: Table compression
>
>
> Actually reading from compressed tables is faster
> than reading from
> non-compressed in systems that don't have their
> CPU's 100 percent busy.
>
> Since the segment size becomes 30% of the original
> size, the system
> requires
> less IO to read the data.
>
> There is a very little CPU overhead needed to
> decompress the data.
>
> Compression is done by building lookup tables for
> repeating values on the
> block level.
>
> Regards,
>
> Waleed
>
>
> -----Original Message-----
> From: Goulet, Dick [mailto:DGoulet_at_vicr.com]
> Sent: Friday, March 19, 2004 3:52 PM
> To: oracle-l_at_freelists.org
> Subject: RE: Table compression
>
>
> Yeah, but what's the penalty during reads???
>
> Dick Goulet
> Senior Oracle DBA
> Oracle Certified 8i DBA
>
> -----Original Message-----
> From: Khedr, Waleed [mailto:Waleed.Khedr_at_FMR.COM]
> Sent: Friday, March 19, 2004 3:48 PM
> To: 'oracle-l_at_freelists.org'
> Subject: RE: Table compression
>
>
> I use it, works great, 60% savings.
>
> Once the table/partition gets flagged "compress",
> any direct load will be
> compressed.
>
> You will get ora-600 if trying to do parallel direct
> load.
>
> Also can't add a column to a compressed table.
>
> Waleed
>
> -----Original Message-----
> From: LeRoy Kemnitz [mailto:lkemnitz_at_uwsa.edu]
> Sent: Friday, March 19, 2004 3:41 PM
> To: Oracle List
> Subject: Table compression
>
>
>
> I am looking into doing some table compression on my
> warehouse database
> to free up some space on the os. I am running
> 9.2.0.4 on Unix 5.1. The
> compression is about 2.5:1 on my tables. The
> documentation says the
> bulk insert time will be doubled but the single
> inserts, updates, and
> deletes are going to be a wash. Does anyone use
> compression? Are there
> any problems you notice in the use of it? I have
> also read that the
> table will need to be re-compressed after the bulk
> inserts. Any
> alternative ideas about getting this done?
>
> Thanks in advance,
>
> LeRoy
>
>

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Received on Sat Mar 20 2004 - 23:00:09 CST