Filtered Indexes Are Tricky

Kevin Eckart investigates filtered indexes not being used:

This warning is telling me that Parameterization is to blame for the filtered index not being used. From here, I see 3 options.

  1. Remove the parameters and use literals. (not practical)

  2. Use Dynamic SQL

  3. Use OPTION(RECOMPILE) at the bottom of the query.

This is the classic issue with filtered indexes: ¬†you expect them to be used, but when you check the plan, they aren’t.

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