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Home -> Community -> Usenet -> c.d.o.misc -> Re: Oracle 8 Partitioning and RAID 5
A copy of this was sent to Gerry Mulcahey <mulcahey_at_travel-net.com>
(if that email address didn't require changing)
On Wed, 24 Mar 1999 19:56:42 -0500, you wrote:
>Hi
>Does anyone see any benefit to using Oracle 8's feature of partitioning
>data in a RAID 5 environment?
>
>As I understand it, partitioning allows you to move parts of a table
>onto other disks thus spreading the IO of the table access. However, if
>your environment is completely RAID 5, how would this help?
>
thats one benefit of partitions but is not the major goal of them.
>Any info appreciated. Please reply to topaze_at_travel-net.com if you have
>any comments.
>
>Thanks,
>
>Ger
Some advantages of partitioning over just raid (or in conjunction with raid)
o divide and conquer: if you have a 1 gig table in one partition and want to reorg or rebuild indexes, you'll work with 1 gig of data. If you have 10 100meg partitions, you can work with 100meg sets of data instead.
o faster recovery from error: if something goes wrong with the raid and you have a 1gig single partition, you'll have to restore 1gig of data. (don't say "its raid -- nothing can happen to it". right after you say that it'll fail). with partitions you can recover each independently of the others.
o partition elimination: if you need to full scan and you have 1 1gig partition -- you'll scan 1gig. On the other hand, you may be able to use partition elimination on 10 100meg partitions to reduce the full scan to 100meg.
o faster mass insert/update/delete: parallel dml (insert/update/delete) is possible with paritions, not so without them.
o faster parallel queries: parallel index range scans are possible with partitions, not so without them.
o "sliding window": if your data has a sliding window to it (eg: keep the last N months of sales data online, age the old stuff off to another system or archive it), partitions let you do this pretty easily -- load and indesx the new data into a table, take the oldest partition and convert it into a standalone table, create a new partition at the 'new' end of the table and switch this new empty partition with the newly loaded data.
there may be others, these just come to mind...
Thomas Kyte
tkyte_at_us.oracle.com
Oracle Service Industries
Reston, VA USA
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