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

From: Greg Rahn <>
Date: Fri, 8 Feb 2008 21:52:38 -0800
Message-ID: <>

If it were an option, I would load into a staging table, build indexes, and partition exchange. This yields the best of all worlds: parallel direct load with no index maintenance, parallel nologging index builds, and doesn't effect queries.

My recommendation: Leverage ASM and not worry about it. You will get the best performance with the least effort.

On 2/8/08, <> wrote:
> 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.


Greg Rahn
Received on Fri Feb 08 2008 - 23:52:38 CST

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