Re: RAID 5 & ORACLE

jon glickman wrote:
>
> If one has RAID level 5, which would give better performance a RAID
> system partioned into 2 filesystems one for index tablespaces and
> another for the data tablepsaces or putting all the datafiles
> of both types of tablespaces all on one large RAID partion?
> There is a index tablespace of a gig or more, should it be
> in one datafile with one extent or striped across a few
> datafiles with an extent in each?

ONE HUGH RAID5 device will stripe everything for you but some crucial points to consider are:

1 Where are you putting your REDO Logs and Archived REDO Logs so they are separate from the rest of the database? ie when your RAID5 dies how do you intend to recover.

2 What "chunk" size is being used for striping across the disks? ie large chunk sizes are better for full table scans while smaller chunk size are better for high update/insert/delete transactions.

3 How many SCSI controller cards are you using? ie if the RAID5 is one large device connected by one SCSI card to your CPU then how fast do you need to get the data from the device, through the controller to the cpu.

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   T T T T T T T T        Bruce Pihlamae
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