Query optimizer can never be perfect, so it makes sense to implement hints to allow user better control the execution.
For instance: "never merge this subquery with others" (`/+ no_merge/`), "treat those tables as leading ones" (`/*+ leading */`), etc.
Hints would enable predictable performance and the planning time would be improved as well.
- duplicates
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CALCITE-495 Support hints to be passed through select/DML commands
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- Closed
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- is related to
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CALCITE-299 Divide the join graph into partitions that can be optimized separately
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- Closed
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CALCITE-481 Add "Spool" operator, to allow re-use of relational expressions
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- Closed
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- relates to
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CALCITE-3519 `inheritPath` of `RelHint` represented by `ImmutableBitSet` may be incomplete.
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- Closed
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CALCITE-3940 Hint item can not parse correctly if the name is right after token "/*+"
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- Closed
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CALCITE-3518 Use List instead of BitSet to keep inheritPath in RelHint
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- Closed
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- links to