Tuning Help !!!!!!!!!!!

[Lani2000]

WILL SOMEONE GIVE ME A HINT?

A system that has only 3 physical disks could be best set up by...........
a. One disk for Oracle executables, one for tables, and one for indexes
b. One disk for Oracle executables and tables, one for indexes, and one for spare space.
c. One disk for Oracle executables and indexes, one for tables, and one for spare space.
d. One disk for Oracle executables, tables and indexes, and two disks for spare space.

[stecal]

Hint - not "e"

[stecal]

Another hint - it begins with "a"

Really, "a" is the answer. Who cares about spare space with three disks? You may never use that much space on a spare space disk, so the disk could pretty much go unused.

A basic rule is to separate tables from indexes. Another is to keep executables separate from data. Combining these rules eliminates b-d, leaving "a" as the best answer.

[chrisrlong]

Originally posted by stecal
A basic rule is to separate tables from indexes.

We've actually been over this topic recently - It turns out this is an example of an old myth that is not true - at least for performance, and that was the topic.

See http://www.dbasupport.com/forums/sho...threadid=30138

It is far more important to know your objects and balance the load on the disks.

- Chris

[pando]

well it's mainly for administrative purposes seperating indexes and data but since Oracle doco likes to say seperate data and indexes (until 9i docu) the answer for this question is most probably a

[stecal]

Well, yes, but the question sounds like an exam question, and those references tend to support separating tables from indexes. Ault's DBA book, page 7, specifically recommends the "a" answer if there are only three disks. Distributing I/O is still an important consideration.

[chrisrlong]

While I sympathize with whatever maintenance issues might exist - I'm a designer/programmer and not a true DBA. So from my perspective, performance trumps maintenance.

With only 3 physical disks (what a ridiculous concept to begin with ), I would think it even more imperative to maximize what little resources you have and do your utmost to balance the load across all 3 disks. Now, I'm not sure how much impact putting datafiles together with the executables/OS might actually have, but even that golden rule might be worth breaking with that few number of disks. As always, IMHO.

Now, if it is an exam question, one would generally want to answer what they want to hear, but otherwise, do what makes sense.

Now that I think about it, I answer what I think no matter who's asking - personal flaw, I guess . I remember writing paragraphs of comments after one of the Oracle exams because a few of their SQL questions were just plain wrong, IMHO.

Anyway, back to sleep...