Description
The existing query hint implementation relies on a logical plan node ResolvedHint to store query hints in logical plans, and on Statistics in physical plans. Since ResolvedHint is not really a logical operator and can break the pattern matching for existing and future optimization rules, it is a issue to the Optimizer as the old AnalysisBarrier to the Analyzer.
Given the fact that all our query hints are either 1) a join hint, i.e., broadcast hint; or 2) a re-partition hint, which is indeed an operator, we only need to add a hint field on the Join plan and that will be a good enough solution for current hint usage.
Attachments
Issue Links
- relates to
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SPARK-26840 Avoid cost-based join reorder in presence of join hints
- Resolved
- links to