Re: performance improvements from putting tables and indexes on seperate disks?

From: Riku Räsänen <>
Date: Fri, 8 Feb 2008 22:18:30 +0200 (EET)
Message-ID: <>

Quick answer: No benefit in 99% of the cases. You will be better off by striping both indexes and data over all the disks.

Search OTN for whitepapers about "SAME" by Juan Loaiza, you should find at least two documents, one describing the "SAME"-architecture and other with a performance comparison.

Oh heck, here is the first (ppt + whitepaper), was unable to find the second:

Btw. Didn't direct load lock the table and prevent it from being queried?

<lainaus kuka="">
> Are there any benchmarks testing whether there are performance improvements on reads and writes
> when you separate data and indexes on separate disks?
> cases:
> 1. sqlloader direct path load of a large number of records to a table with 4-5 indexes. The
> indexes can't be dropped during loads since queries take place during the load.
> My understanding is that the write process is serial so separating the data and indexes onto
> separate disks will not improve performance much. I don't have the disks to test this on right
> now.
> 2. queries. mainly oltp type queries. any performance improvements for separating the hard disks
> that tables and indexes are on?
> This is on a SAN, but we can have it configured to give us separate disks and show them to us as
> separate mount points.
> --

Riku Räsänen
Kantamestarit OY

Received on Fri Feb 08 2008 - 14:18:30 CST

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