Originally posted by DreamWarrior
An index is built based on what is IN a table, PERIOD! Indexes for everything NOT in the table do not, and can not, exist.
Ofcourse, but is it relevent here to the post?

Querying data using NOT will have to fetch records that does not match equality contition, Ok does that mean Index for NOT can not exist..i really dont understand what do u mean here.


BTW, with queries using NOT will not use INDEX only because it has to do INDEX FULL scan and the table access by ROWID which will be much costlier in terms of I/O ( Full Scan will fetch only 1 block per i/o where as FTS can DMBC blocks per I/O )

Abhay.