Re: Reorg'ing TBSs

Sonya,

You should spread your large tables and tablespaces over several devices. This is generally good tuning advice and having done it at several installations where speed on large tables has been a problem, it definitely works. If you have 8i, use the partitioning tools otherwise, size your datafiles appropriately, so your tables are spread over several devices. If you have some really large tables, you may even consider giving each its own tablespace. Remember to keep your indexes in a tablespace of their own, on a device away from the data, if possible.

Doing an export with compress=y is also a good idea. This reduces fragmentation, though you need to make sure that you have enough datafile space to take the size of the new initial extent.

On the RAID5 front, I'd advise AGAINST it on a performance point of view. Again, I've been involved with large installations running on RAID5 where it has been removed and seen a huge performance gain from the database. Oracle themselves recommend mirroring rather than RAID5 and they have also said that if you do use RAID5, you should always keep your redo logs on another disk outside the array.

Hope this helps!

Regards

James

www.jamesbelton.co.uk

<tandym_at_hotmail.com> wrote in message news:8j8aoq$qe1$1_at_nnrp1.deja.com...
> Okay-
>
> spreading VLTBSs out over several devices makes the read time faster.
> What if you do an export with compress=y and import the data to a new
> system. What would be better, put the one VLTBS on a single device, or
> a RAID 5 array? Wouldn't the RAID speed it up? or would it actually
> slow it down? (we are talking 14 GB Tablespaces)
> Thanks in advance.
>
> sonya
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Tue Jun 27 2000 - 00:00:00 CDT