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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Impala 2.7.0
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None
Description
Many join types never return any rows if the build side is empty. In these cases we still process the whole probe input instead of short-circuiting the evaluation.
E.g. the following query unnecessarily scans the whole of lineitem.
select * from tpch_20_parquet.lineitem inner join tpch_20_parquet.orders on l_orderkey = o_orderkey where o_comment = 'no matches for this comment';
This also affects subqueries, e.g. IN() that are rewritten to joins.
Attachments
Attachments
Issue Links
- is blocked by
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IMPALA-3990 ExchangeNode::Close() cancel sender fragment if called before eos
- Open
- is related to
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IMPALA-5789 Prune all partitions if an always-false runtime filter is received
- Resolved