It is useful to have rules reducing Exchange/Sort/SortExchange keys, e.g.,
SELECT key,value FROM (SELECT 1 AS key, value FROM src) r DISTRIBUTE BY key;
can be reduced to
SELECT 1 AS key, value FROM src; # Since singleton requirement may already required by SELECT.
SELECT key,value FROM (SELECT 1 AS key, value FROM src) r ORDER BY key;
can be reduced to
SELECT 1 AS key, value FROM src; # Since ordering on constant is useless.
- is related to
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CALCITE-2729 Introducing WindowReduceExpressionRule
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- Closed
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- links to
