----- Original Message -----
Sent: Thursday, September 25, 2003 4:34
PM
Subject: RE: Oracle Compress Option
Disk is not
cheap if you pay for high availability configuration. I compress historical
data on daily basis and was able to save 70 percent of the disk space. Imagine
the amount of savings for five TB.
Two major
issues:
1) Oracle says
updates will be slow on compressed tables, but I say don't even try to update
a compressed table, uncompress first otherwise you will end up with a segment
that is not good at all for scattered reads.
2) You can not
add columns to the table when it's compressed, so if you compressed a big
table and need a new column you need to recreate the table without
compression. So adding many extra columns before compression is a good
idea.
It's mainly
good for data warehouses applications.
Regards,
Waleed
I think 9202 doesn't like to export compressed tables in
direct mode ... so watch out for that ... I implemented, tested and next day
reverted back to regular tables due to this export issue. Disk is
cheap.
A BAARF party member wannabe !!
Raj
--------------------------------------------------------------------------------
Rajendra dot Jamadagni at nospamespn dot com
All Views expressed in this email are strictly
personal.
QOTD: Any clod can have facts, having an
opinion is an art !
-----Original Message-----
From:
Mogens Nørgaard [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, September 24, 2003 10:05 PM
To: Multiple recipients of list ORACLE-L
Subject: Re: Oracle Compress Option
"Compress to impress?" by Julian Dyke is a good presentation
on this
topic (see for instance http://www.ukoug.org/calendar/jan03/jan30ab.htm).
I do have the article - 202 K with no compression, 147 K
with
compression :).
Let me know if you're interested, and I'll email it directly
to you.
Mogens
[EMAIL PROTECTED] wrote:
>Does anybody has any experience with Oracle 9I
compression option. I did some test on 9202 with a table of more 14 million
rows. Table has total 7 indexes. Surprising both table and indexes are using
more space after compression. Before compression space used is 13064MB and
after compression 13184MB. In both the cases I did export from source table
and stored in two different tablespaces. Any insight on that and any
disadvantages of using that.
>
>Thanks
