RE: Partitioning opinion

  • From: "Leslie Tierstein" <leslie.tierstein@xxxxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 31 Aug 2004 12:19:40 -0700

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@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Harvinder Singh
Sent: Tuesday, August 31, 2004 1:02 PM
To: oracle-l@xxxxxxxxxxxxx
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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