Details
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Improvement
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Status: Open
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Minor
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Resolution: Unresolved
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Description
Most of the code inside the nested while loop can be extracted and computed only once in the external loop. Moreover there are catch clauses for NPE which seem rather predictable and could possibly be avoided by proper checks.
In addition the code should be adapted to handle the case of multi column semijoin reducers introduced by HIVE-21196.
The goal of this issue is to refactor TezCompiler#markSemiJoinForDPP method to avoid redundant operations, improve code readability, and handle multicolumn semijoin reducers. As a side effect of this refactoring the method will be slightly more efficient although unlikely to have observable difference in practice.