| avnish |
Posted: Dec 27, 2007 01:33:30 AM |
Total Post: 53
Joined: Dec, 2007
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Hi,
Can any one tell me how oracle indexes are work. Is there is any algorithm they follow. or is there any execution plan for indexes set by oracle.
oracle says index save to full scan of tables when need somthing from table... how indexes save full scans?
Thanks in advance...
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 Murtuja |
| Posted: Dec 27, 2007 03:04:24 AM |  |
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Total Post: 814
Joined: Jan, 2006
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Hi,
Do you have any book for Oracle DBA ? You can read from it.
Google is always useful for understanding any concept.
http://www.dbazine.com/oracle/or-articles/burleson18
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| Mohammed Taj |
| Posted: Dec 27, 2007 07:45:04 AM | |
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Total Post: 694
Joined: Jul, 2007
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http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/schema.htm#CNCPT811
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| MOH_DBA |
| Posted: Dec 27, 2007 02:10:09 PM | |
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Total Post: 123
Joined: Nov, 2007
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The Concept of the index is simple.
when you create an index on a column, Oracle will create rowid and column value entery in the index.
So when a select come, and the where clause contains an indexed column, then Oracle will not go to the table, it will go to the index and search their and when it find the value it will see the rowid which points directly to the logical row in the table.
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