SQL Server Performance Forum – Threads Archive
Raid for Datawarehouse
I need some info about implement raidfor datawarehouse Can you help me
Well the one thing I can tell you is for a datawarehouse, you want a fast read solution. The best RAID out there is RAID10 (RAID 1+0). If you can’t do that, then do RAID 5, which offers the next best read solution.
"How do you expect to beat me when I am forever?"
If your SQL Server will be a data warehouse only, and not be subject to data modifications, either RAID 5 or RAID 10 will be equally OK. RAID 5 is great for reading data, but poor for data modifications. But if you are only reading data, then RAID 5 will work just about as good (and it much less expensive). The key to fast reads, using any RAID, is to have a fast controller and lots of disks per channel. Find out from your vendor what they recommend for the maximum number of disks for the controllers they sell.
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Brad M. McGehee
Webmaster
SQL-Server-Performance.Com
what about my Tlog and the Tempdb
Do you mean to say that you will be creating temp tables in this data warehouse? If you have SQL Server 2000, look into table variables.
"How do you expect to beat me when I am forever?"
In data warehouses, the transaction log is not used much, so its placement is not critical. I would probably place it on the same RAID array as your data. Your tempdb database may or not be very busy. If you expect it to be busy, consider putting it on its own RAID 1 array. See my website for more information on how to optimize the tempdb database.
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Brad M. McGehee
Webmaster
SQL-Server-Performance.Com
I am curious how TempDB would be used in a DW? If you have an existing environment I would suggest that you collect some performance monitor data on the disk drives to determine how much writing will be done. If there is a lot I would go with RAID-10 if there isn’t I would go with RAID-5.
Sorting and GROUP BY operations in a data warehouse would make use of the tempdb.
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Brad M. McGehee
Webmaster
SQL-Server-Performance.Com
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