Performance issue

[johan]

I was wondering if someone can tell me what's preferable in performance matter, when you determine where the "DB-files"
should be placed?

control01.ctl
control02.ctl
control03.ctl
indx01.dbf
rbs01.dbf
redo01.log
redo02.log
redo03.log
system01.dbf
temp01.dbf
tools01.dbf
users01.dbf

Which files should be on a different partition? Different disk?

Does someone know?

Any links to some documentation regarding this?

Thanks
/Johan

[johan]

By default the files all is placed in the sam directory....
(typical installation)

oradata/SID/..

So the question is how important the placement of these files are...

Someone with experiences?

/Johan.....again..

[sambavan]

First of all you would want to spread your redo files, control files on to multiple disks. Then spread the index and the data into two disks. Then the others. Say for example that you have four disks, then you would juggle it accross the four disks and monitor the for the hot disks and then rearrange it.

Plan your database
Tuning I/O



Sam

[Edited by sambavan on 10-09-2001 at 10:57 AM]

[dknight]

I suggest you look for documentation on the Optimal Flexible Architecture (OFA). In addition, the Oracle DBA Handbook has a section devoted to your question.

Here are some ideas:

1. Put your control files on different disks if possible.
2. Put your redo log groups on different disks.
3. Separate your data and your indexes on different disks.

Points 1 and 2 support easier recovery. Point 3 helps performance by distributing I/O over different devices.

Good luck.

[johan]

Thanks alot!

But say for example I've already installed my DB on
1 disk and "all files" under oradata.

Is it possible to move these files without having to recreate the database?

Do I do something like this?

* Create some filesystems on new disks...
* Stop the database..
* Move th files to the new filesystems (redolog control..and so on)
* Change the parameterfile initSID.ora (to point out the new paths)
* Start the DB



[Edited by johan on 10-10-2001 at 03:21 AM]

[johan]

I succeed in moving the controlfiles to a different filesystem
since they was specified in the parameterfile. (initSID.ora)

But how abouy my redolog-files?

They aren't specified inte the "pfile"...

[mageri]

Hi,

I think you have three loggroups with one member each. Am I right? You have to multiplex the redo log files with more members on another device. In this case you don't have to shutdown the database.

ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo01_2.log' TO GROUP 1;
ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo02_2.log' TO GROUP 2;
ALTER DATABASE ADD LOGFILE MEMBER
'another device:/some directory/redo03_2.log' TO GROUP 3;

Good luck!