Query Optimization Techniques - Tips For Writing Efficient And Faster SQL Queries

Tip #1: Use Column Names Instead of * in a SELECT Statement Tip #2: Avoid including a HAVING clause in SELECT statements Tip #3: Eliminate Unnecessary DISTINCT Conditions Tip #4: Un-nest sub queries Tip #5: Consider using an IN predicate when querying an indexed column Tip #6: Use EXISTS instead of DISTINCT when using table joins that involves tables having one-to-many relationships Tip #7: Try to use UNION ALL in place of UNION Tip #8: Avoid using OR in join conditions tip #9: Avoid functions on the right hand side of the operator Tip #10: Remove any redundant mathematics