The query optimizer decides on plans to use for certain queries, then memorizes that plan for the next 1,000 queries of that type (unless indexes change etc).
It would be really useful to have this information visible. It could be a good way of discovering what indices are being used for what queries. It could also then be used to find unused indices.
- is related to
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SERVER-8871 Support admin hints per query pattern
- Closed
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SERVER-12358 Add query plan history and logging
- Closed