Composite Index Performance

[dnivraramuk]

Hi all,

I wanted to know about the performance of the indexes when I create a composite index on F1,F2,F3 on the three columns below:

F1 F2 F3
|20030203|CA |098765|

Or to concat the above field into one, and create a singal index on the whole field as below (F1), as my queries will always use this three combination together.

F1
|20030203CA 098765|

Any document that state this difference clearly will really be very helpful.

Regards,
Arvind