I've been investigating some databases using the [dm\_db\_missing\_index\_group\_stats](http://msdn.microsoft.com/en-us/library/ms345421.aspx) DMV, and have a question about the `equality_columns` field in the [dm\_db\_missing\_index\_details](http://msdn.microsoft.com/en-us/library/ms345434.aspx) view.

MSDN says that this holds "a comma-separated list of columns that contribute to equality predicates of the form: *table.column = constant value*"

I have a table which is represented in three of the highest cost missing indexes, with the following equality columns:

* `client_product_id`
* `client_id`, `client_product_id`
* `client_id`, `client_product_id`, `status`

Does the order of the columns in the second and third index groups matter? e.g. if I created an index on `client_product_id`, `client_id`, `status`, it seems that it should satisfy all three missing index cases, on the grounds that a query like `client_id = 123 AND client_product_id = 456` should be satisfied equally regardless of whether `client_product_id` or `client_id` comes first in the index definition.

(obviously if it was an inequality predicate, this would not be the case)