Speed of PrimaryKey vs Index

I am using Oracle with Delphi (using a TTable and TDBGrid - this is not necessary to know).
I am using a grid component to display my data. When the data is sorted on the primary key, it navigates very quickly. However, if I switch the sort order to the Index key, it moves very slowly.

I then dropped the indexes and primary key, and then defined the primary key as the column which was previously the index. It navigates fine. This makes me conclude that there is a difference in the speed between a primary key and a index key. Would anyone have any idea why the indexes are working so slowly?

Stan. Received on Wed Mar 03 1999 - 14:11:19 CST