Re: Size of physical datafiles ..URGENT!!!!!

Soumitra Bose (sbose_at_ctp.com) wrote:
: Hi ,
:
: ORacle popular wisdom suggests that in any unix environment if the size
: of the datafile goes beyond 1GB ,the performance drops down abruptly .
: Now generally the diskdrives in HP does not come below 2GB (at least).
: If I put in two datafiles there with 1GB , for all practical purposes it
: is just two logical data-files but phyisically it would look like one
: datafile with more than 1GB (in this case 2GB) size . Am i first of all
: correct in making the above assumption ????
: What is the best way of getting around it .
: I need a huge number of physical data mount points for the installation
: I am working on ...Any advice . I guess the RAID 5 level or RAID Array
: architecture would not do any good , am I right ?>?????
: Please advise .....
: Thanks

Soumitra,

This is the first that I have heard that performance drops abruptly past 1GB in Unix. This is not true in my experiences. Perhaps you should investigate the performance of your drives/controllers.

Your next assumption is wrong. Two datafiles (1 gig each) will physically look like two datafiles. In Unix, do an "ls" and you will see two files. However, what I think you are getting at is that having them both on the same drive will not effectively spread i/o. In this you are correct, and you should spread the datafiles over different drives and if possible controllers.

RAID will help you. The best method of spreading files is by using Oracle's OFA. Seperate system, temp, rbs, tables, indexes, etc. according to the OFA guidelines.

-Ari Kaplan
Independent Oracle DBA Consultant

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