Avoid using local variables in your Select statements

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Avoid using local variables in your Select statements(sqlprof.com)

submitted by ericvaillancourt(90) 4 years, 1 month ago

People are always surprised when I tell that their queries will run slower when they use local variables in their queries. Let me explain: If you use a local variable in a query predicate instead of a parameter or literal, the optimizer resorts to a guesstimate for selectivity of the predicate. Use parameters or literals in the query instead of local variables, and the optimizer will do a better selecting a query plan. For example, execute both of these queries.

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