Angie,
You can use the QueryAnalyzer and it's Show Execution Plan feature to examine what SQL plans to do with the query. It will give you a nice graphical representation of the query. In general if it says it's going to be doing a TABLE SCAN if there is no useable index and generally that's bad (ie slow).
You can also use the index optimizer to let the database determine what indexes will best support the queries being run.
>Thank you so much for clarifying the issue. It is greatly appreciated!