[AccessD] [dba-SQLServer] Raid for reliability on SSDs

An index that contains the columns of the most common queries.



On 6/13/09, William Hindman <wdhindman at dejpolsystems.com> wrote:
> ...mind if I ask wtf is a "cover index"?
>
> William
>
> --------------------------------------------------
> From: "jwcolby" <jwcolby at colbyconsulting.com>
> Sent: Saturday, June 13, 2009 8:00 PM
> To: "Access Developers discussion and problem solving"
> <accessd at databaseadvisors.com>; "Dba-Sqlserver"
> <dba-sqlserver at databaseadvisors.com>
> Subject: [AccessD] Raid for reliability on SSDs
>
>> I have a very unique situation which I have discussed in other emails.
>> The situation is that I have
>> a SQL Server database where I intend to place just cover indexes (assuming
>>
>> I can do that) into
>> database files out on a RAID of SSDs.  The main database tables will
>> continue to reside on a normal
>> raid 6 array.
>>
>> My question is, if I have the original READ-ONLY data tables on a raid 6
>> array, and I am just
>> building cover indexes into a RAID of SSDs, is it necessary to use a
>> "redundant" array, or can I
>> just go RAID 0 with no redundancy.  SSDs are still quite expensive and if
>> I could go with 2 or 3
>> 120g SSDs RAID 0 I would get much better read speed and more volume size
>> than if I used the same
>> number of drives RAID 5.  IOW if a drive fails so what?  The table used to
>>
>> generate the cover index
>> sits out on a fully protected RAID 6 array.
>>
>> --
>> John W. Colby
>> www.ColbyConsulting.com
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>>
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