feat: Naive deduplicating recursive CTE implementation#18184
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Tpt wants to merge 1 commit intoapache:mainfrom
Closed
feat: Naive deduplicating recursive CTE implementation#18184Tpt wants to merge 1 commit intoapache:mainfrom
Tpt wants to merge 1 commit intoapache:mainfrom
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- introduce a new "result table" intermediate table storing all already emitted results - use existing physical operators to deduplicate the output of both static and recursive terms and remove from the recursive term output the already emitted results - add a simple test of a transitive closure on a cyclic graph
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Much better implementation in #18254 |
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This is very naive and slow. It would be much better to build the result table as a hash table inside of
RecursiveQueryExecand use if for deduplication, removing the need for any extra operator. I guess it will requires significant coding because we need an incremental hash map (build and probe steps are interleaved).Edit: made it a draft, I want to experiment with hash table first.
UNIONin recursive CTE #18140