[GitHub] spark issue #18692: [SPARK-21417][SQL] Infer join conditions using propagate...

[Aklakan <gi...@git.apache.org>]

Github user Aklakan commented on the issue:

    https://github.com/apache/spark/pull/18692
  
    Hi, its unfortunate to see this PR having gotten reverted
    
    @gatorsmile 
    > After rethinking about it, we might need to revert this PR. Although it converts a CROSS Join to an Inner join, it does not improve the performance.
    
    The point of this issue is not performance improvement, but that (in our case *automatically generated queries*) *do not work at all* with SPARK, whereas there is no problem with these queries in PostgreSQL and MySQL.
    
    @aokolnychyi 
    ```IN``` are not equals-constraints (even though they could be expanded: `a in (x, y, z) -> a == x OR a == y OR a == z`), so your example does not apply to join inference of literals.


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