indexing "select" columns

From: Leon <lrzhemov_at_home.com>
Date: 4 Jun 2001 13:32:09 -0700
Message-ID: <8cb139cf.0106041232.192801d6@posting.google.com>

I hope Oracle would use only index to select information from the table as soon as all information is present in an index, so select col2
from table1
where col1= value
would use only index as soon as index
CREATE UNIQUE INDEX12 ON table1(COL1, COL2) exists
Unfortunately statistics for select like that shows that speed of this query is exactly the same as with index "CREATE UNIQUE INDEX1 ON table1(COL1)"

Does anybody has good experience in using "index only" (simulating IOT) queries?
Potentially it should be faster then IOT as soon as indexes could be cached in memory but IOT can't.

Thanks
Leon Received on Mon Jun 04 2001 - 15:32:09 CDT