Re: LARGE DATABASES-UNIX SUN SOLARIS 2.4

David Bellamy (bellamy_at_commerce.uq.edu.au) wrote:

: Raw partitions are supported, but are not really recommended unless you
: know what you are doing. They provide slight (10-30%) performance
: improvement but are much harder to manage, backups etc. They also look

10-30% performance improvement may not look like much, until you have a sizeable database to manage. I have an application where the dataload takes 5 hours a day to update the database. A 30% performance improvement here is significant!

: like unused partitions on partition maps. Do you really want to go on
: holiday and some junior sys prog looking for some spare space decides to
: .... :-)

I suggest that root password be severely restricted just on general principals. If you have a shop where the junior programmers have root access, you're eventually going to have a disaster, anyway.

: If you need large tablespaces, then just use multiple files per
: tablespace. Each file can be 2GB. The filesystem restriction is
: somewhere about 4TB.

Be sure to use a clean disk for Oracle tablespaces/datafiles. Just adding a tablespace to an in-use disk is asking for a performance hit. The amount would depend on the usage patterns for the disk, and how many "holes" were filled when creating the datafile. It's best to just reserve a complete partition/slice for Oracle datafiles, and use it up completely if you use it at all. However, in some applications, where I/O wait time is unacceptable, you might even want to have disks with relatively large areas of unused space to help improve average seek times.

In cases where your database is very small, or response/process time is not important, it's OK to share a disk between Oracle and other applications. However, in general, if a disk has a tablespace on it, nothing else should be on the disk. Even if a large percentage of the disk is left unused.

Later.

--
Bob Stewart                     ASE
(310) 335-7152                  Air Transportation Division
bob_at_latcost1.alaao.ats.eds.com

I am definitely NOT speaking for EDS.