[jira] [Created] (CALCITE-4990) Add SetOpFilterMergeRule for Converting UNION with same inputs but different filters to single input with OR Filter

["yanjing.wang (Jira)" <ji...@apache.org>]

yanjing.wang created CALCITE-4990:
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             Summary: Add SetOpFilterMergeRule for Converting UNION with same inputs but different filters to single input with OR Filter
                 Key: CALCITE-4990
                 URL: https://issues.apache.org/jira/browse/CALCITE-4990
             Project: Calcite
          Issue Type: Wish
          Components: core
    Affects Versions: 1.29.0
         Environment: The attached diagram illustrates how the new rule works.

 

!UnionAllToOr.png!

The rule will be useful when Input Sub Tree is a computing-intensive or large IO operation, 

and it works for N-way Union, not just 2-way Union. In addition, The Project operator will be optional present.

 

It has some prerequisites when applying the rule to rel.

1. Project and Input Sub Tree must be identical.

2. For UNION: 
New Filter = left Filter OR right Filter.

For UNION ALL: 

left Filter, right Filter must have no overlap.

 

Example:

 
{code:java}
SELECT a, b FROM t WHERE c = 1 
UNION ALL 
SELECT a, b FROM t WHERE c = 2 
UNION ALL 
SELECT a, b FROM t WHERE c = 3  {code}
After applying the rule, we get

 

 
{code:java}
SELECT a, b FROM t WHERE c in (1, 2, 3)  {code}
 

 

 

 
            Reporter: yanjing.wang
            Assignee: yanjing.wang
             Fix For: 1.30.0
         Attachments: UnionAllToOr-1.png





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