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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Multiple Datafiles and performance?
If by "multiple datafiles that ..." you mean for a single tablespace then:
It's possible to stripe a tablespace across drives "by hand", but it is no substitute for real, genuine hardware or software striping. I'm a little foggy on the "by hand" process since (I think) it is considered an archaic practice; but I'll give it try here. Through a process of creating a datafile, then creating a segment, then creating another datafile, then creating another segment or adding extents, etc. try to force the data to be as equally distributed as you can get it. It's a labor intensive process and requires constant fiddling to keep things in balance if the amount data in the database is constantly changing; and it works only if the data is accessed in a completely random manner. You must manually distribute the data equally among the data files and keep it equally distributed as things change. So *NOBODY* does it.
If by "multiple datafiles that ..." you mean multiple tablespaces with tables distributed among the tablespaces in such a way as to achieve balanced I/O (or reasonable facsimile thereof) then:
Hell yes!
Busting up tablespaces into multiple data files just to be busting them up results in a database that is a big turd to maintain; and you end up with your free space scattered all over hell and half of Texas.
And right now I have
http://tinyurl.com/jaq4
in the CD drive. And it's on track 5:
Gay Gordons / Camerons/ Brown Haired Maiden / SCOTLAND THE BRAVE.
I'm ready for a fight now. Anybody want to fight?!!
(No I'm not Scottish; but if it isn't Scottish it's still CRAP)
>
> Oracle 8.1.7.4
> Win2k
>
> What is the consensus on datafile sizing and the impact/overhead
> multiple datafiles have on performance?
>
> For example, if I have one 2.5g datafile, and three 1g
> datafiles, and I
> need more space, would it be better to increase the size of
> the 1g to
> 2g or add another 1g datafile?.
> Is it better to keep them all uniform in size?
>
> I would think having multiple datafiles that could be spread across
> drive volumes would be beneficial, am I wrong? (Wouldn't be the first
> time :)
>
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Stephen Lee INET: Stephen.Lee_at_DTAG.Com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Thu Aug 07 2003 - 10:14:24 CDT
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