RE: Duplicate rows
- From: "David Kurtz" <info@xxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 2 Jun 2004 12:50:33 +0100
Presumably you have a delete statement that looks something like
DELETE FROM <table> t1
WHERE EXISTS(
SELECT 'x'
FROM <table> t2
WHERE t1.<key> = t2.<key>
AND t1.rowid < t2.rowid
AND rownum = 1)
;
A non-unique index on the key fields should improve the performace of this
query.
How did the non-unique data get in there in the first place? Is there any
condition on t1 that you could use to cut down the number of rows that the
driving query will return? If your are trying to delete 5000 out of
millions of rows then this isn't going to be quick either.
_________________________
David Kurtz
Go-Faster Consultancy Ltd.
tel: +44 (0)7771 760660
fax: +44 (0)7092 348865
mailto:david.kurtz@xxxxxxxxxxxxxxx
web: www.go-faster.co.uk
PeopleSoft DBA Forum: http://groups.yahoo.com/group/psftdba
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Computer Centre -
NIIPL
Sent: 02 June 2004 10:57
To: ORALCE LIST
Subject: Duplicate rows
Dear All,
One table is having more than 5000 duplicate record. We would like to remove
all the duplicate records.
Using rowid method, it takes much time to execute.
Is there any other way to remove all the duplicate rows in a faster manner.
Regards,
Balu
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