About SQL Hints
* A hint is an instruction to the optimizer to follow an ‘application developer desired’ execution plan
* Make decisions for the optimizer because you have more in-depth knowledge about data distribution patterns
* In a test or development environments, hints are useful for testing the performance of a specific access path- test use of a specific index when there are several indexes defined on the same table
* Changes in the database or host environment can make hints obsolete and even have negative consequences
* Recommended to use tools like SQL Tuning Advisor, SQL plan management, and SQL Performance Analyzer, to address performance problems not solved by the optimizer before considering hints
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