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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Partitioning opinion
So we want to create Global indexes only if we want them to be
non-partitoned or have different range partitioning key otherwise we can
create non-prefix local indexes for all the non-key columns.
Then if our goal to implement partitioning is to have archive/dearchive
functionality then we might not need global indexes.
Is this correct or I am missing something subtle here?
Thanks
--Harvinder
-----Original Message-----
From: Leslie Tierstein [mailto:leslie.tierstein_at_visionchain.com]=20
Sent: Tuesday, August 31, 2004 3:20 PM
To: oracle-l_at_freelists.org
Cc: Harvinder Singh
Subject: RE: Partitioning opinion
In our experience, non-prefix local indexes work fine. They essentially give another access path to the data, in addition to via partition pruning. I think it shows up as a fast full scan, and performance is adequate for our reports. (Oracle 8i and 9i with 300 million+ rows per partition)
All of our indexes are local, but we have to do deletes/truncates on data in the partitions, and global indexes didn't give the performance we needed. (To be more blunt: Your delete when archiving will perform horribly.)
We have also placed the partitions in different tablespaces, so our backup strategy can take into account making the tablespaces read-only as their date range is passed.
Sorry this is anecdotal and I don't have the performance stats. They're on a client's system which I don't have access to today. But I have vivid memories.
Leslie
Leslie Tierstein
Senior Consultant
Vision Chain, Inc.
The first software to power the demand data network
phone: 202-261-3549
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Harvinder Singh
Sent: Tuesday, August 31, 2004 1:02 PM
To: oracle-l_at_freelists.org
Subject: Partitioning opinion
Hi,
We have a table having 14 columns and contain historical data and we are
planning to implement partitioning so that we will keep only 12 months
data online and purge the old partition every month. We will be using
Range partitioning on Date column name Interv and have primary key on
(id,Interv). Data is never updated and only deleted for archiving that
we are planning to do as drop partition so for most of the time only
inserts will go against this table and few Selects. For performance of
select we have to add 2 more non-unique global indexes. So the schema
will look like:
Primary key index on (id,Interv)
Does non-prefix local indexes be Ok or we should change the order of PK
to (interv,id) to have prefix local index?
Non-unique index on 3 columns
Non-unique index on 3 columns
Should we partition these global non-unique indexes or it does not
matter since partitions will not be used by optimizer for pruning?
Thanks
--Harvinder
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