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Hari Sankar Sivarama Subramaniyan commented on HIVE-5771: --------------------------------------------------------- The restriction related to vectorization in ConstantPropagate::transform() can be lifted once HIVE-7514 is committed. Vectorization will benefit from this fix, so it is better to make this change. > Constant propagation optimizer for Hive > --------------------------------------- > > Key: HIVE-5771 > URL: https://issues.apache.org/jira/browse/HIVE-5771 > Project: Hive > Issue Type: Improvement > Components: Query Processor > Reporter: Ted Xu > Assignee: Ted Xu > Attachments: HIVE-5771.1.patch, HIVE-5771.10.patch, > HIVE-5771.11.patch, HIVE-5771.12.patch, HIVE-5771.14.patch, > HIVE-5771.16.patch, HIVE-5771.2.patch, HIVE-5771.3.patch, HIVE-5771.4.patch, > HIVE-5771.5.patch, HIVE-5771.6.patch, HIVE-5771.7.patch, HIVE-5771.8.patch, > HIVE-5771.9.patch, HIVE-5771.patch, HIVE-5771.patch.javaonly > > > Currently there is no constant folding/propagation optimizer, all expressions > are evaluated at runtime. > HIVE-2470 did a great job on evaluating constants on UDF initializing phase, > however, it is still a runtime evaluation and it doesn't propagate constants > from a subquery to outside. > It may reduce I/O and accelerate process if we introduce such an optimizer. -- This message was sent by Atlassian JIRA (v6.2#6252)