Question

How can I compare the performance of an Index on a table using the Query Analyzer?

I would like to run the same query through the Estimated Execution Plan twice, once using the index and once without, and have a good comparison of the table scans/index scans that are generated.

I have tried CREATE INDEX…, SELECT…, DROP INDEX…, SELECT. I expect the first query to use the index and the second to have no index, but both execution plans will use the index.

Answer 1

The technique that ended up working for me was to use the WITH keyword in the FROM clause.

When the index is created:

SELECT * FROM table WHERE ...

SELECT * FROM table WITH (INDEX(0)) WHERE ...

The first query will (probably) use the index, the second will not.
You could also use multiple indexes like:

SELECT * FROM table WITH (INDEX(IX_test1)) WHERE ...

SELECT * FROM table WITH (INDEX(IX_test2)) WHERE ...