| High Disk i/o performance problem [message #56730] |
Mon, 21 April 2003 02:57  |
Atieno
Messages: 1
Registered: April 2003
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Junior Member |
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I have a table which has around 12,00,000 records. Even a simple sql query without any joins causes a high disk i/o performance problem on this table. Oracle version used is 7.3.4.4. I have checked the following :
Cache Hit ratio = 95%
reloads/pin ratio = 0.17%
Can any setting be done to increase this performance. I tried creating an index on the high selectivity columns in the table which are used in the query but didnt help. Can anyone help me with this. Moreover in this case does the query need to be tuned or some other init.ora settings will have to be changed. Can anyone help....
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| Re: High Disk i/o performance problem [message #56736 is a reply to message #56730] |
Mon, 21 April 2003 22:26  |
Prasad
Messages: 104
Registered: October 2000
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Senior Member |
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Hi
You Check U'r Sql statement using EXPLAIN PLAN & check whether it is using any full table scans, If U have set optimizer_mode=cost then analze table
sql> analyze table compute statistics for all indexes;
and also increase db_file_multiblock_read_count=32.
I think by this settings u'r query should work fine.
Regards
Prasad
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