| Increasing performance of queries [message #140718] |
Wed, 05 October 2005 06:17  |
sreek_s
Messages: 45
Registered: May 2005
Location: Andaman Nikobar
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Member |
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Hi,
Following queries are taking too much time to execute. Please help me to increase the performance of those queries.
1. I have a table which has large data (lakhs of records). I need to delete some of the rows based on a condition. Currently it is taking 20 minutes to execute a single delete query on such a table. How can i increase the performance of delete query?
2. Also i have some merge queries. They are also taking long time to execute. In this case also table has lot of data. How can i increase the performance of merge query ?
Note:- In both the above cases , the tables which i am operating on are having indexes. Is the performance degradation because of indexes ?
Please suggest me the best ways to increase performance of queries.
Regds,
Srikanth
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| Re: Increasing performance of queries [message #140726 is a reply to message #140718] |
Wed, 05 October 2005 07:10  |
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Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
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Senior Member
Account Moderator |
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No information about oracle version, os,available statistics / plan / trace , data distribution etc.
With the wealth of available information, let us start guessing.
>>1. I have a table which has large data (lakhs of records). I need to delete some of the rows based on a condition. Currently it is taking 20 minutes to execute a single delete query on such a table. How can i increase the performance of delete query?
When was the last the statistics collected?
COllect the statistics on table and indexes.
try again.
1 lakh=100,000.
Out of lakhs for records, how much are you deleting?
Please look into the following discussion , apply them and see whether it helps.
http://www.orafaq.com/forum/t/51172/0/
Thanks & Regards
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