Title: RE: Oracle Compress Option
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ethernet ... gBit ...
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 !
Thanks for the information.
One more question, is your interconnect ethernet
based or proprietary such hyperfabric for hp etc..
Thanks,
Tanel.
----- Original Message -----
Sent: Thursday, September 25, 2003 6:19
PM
Subject: RE: Oracle Compress
Option
we have 2 gbit private interconnects of which only one is used at any
given time. Everyone else talks to the dbs using public network. Both are
active/active. On one instance luckily we have application partitioning one
side manages the feeds that come from every foot/bast/basketball, hockey and
scores of other games and processes them and sends it out to customers.
Another side takes this data plus people sitting to make corrections if any
before it is fed to video generators and goes on espn network broadcast. So
it works fine.
Other instances are legacy ... the active/active is more like a HA
configuration, lots of people connected on either side all the time lots of
DML activity going around all the time. We see more of a GC traffic ... but
we are experimenting with _fairness_threshold parameter to see if that will
help. As for performance issues, we encounter lots of BBW but unfortunately
that is due to business logic and can't be easily
changed.
Otherwise we do fine.
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 !
Hm, interesting...
How does your active-active config work, do
you have write activity on all nodes?
I'd be interested in any performance issues
you had or currently have...
Have you partitioned your application or data
usage somehow?
What kind of interconnect you're
using?
Tanel.
----- Original Message -----
Sent: Thursday, September 25, 2003
4:49 PM
Subject: RE: Oracle Compress
Option
Waleed, I get your point ...
We have 6 RAC instances that run active-active ...
and compared to availability requirements, we (incl management) decided
that disk is cheap.
I guess it is relative ...
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
!
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
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