AdamGS opened a new issue, #21309:
URL: https://github.com/apache/datafusion/issues/21309

   From the [Story of 
Joins](https://www.cs.cmu.edu/~15721-f24/papers/Story_of_Joins.pdf) paper, for 
queries like:
   ```sql
   select Title, ECTS = any (select ECTS from Courses c2
   where Lecturer = 123) someE‘ual
   from Courses c1
   ```
   > The result column someEqual can have the values TRUE, FALSE, and NULL 
(i.e.,
   unknown). Accordingly, some care is needed to implement the mark join 
correctly, as we
   will discuss in Section 5. But the great benefit is that we now translate 
arbitrary exists/not
   exists/unique/quantified-comparison queries into a join construct and 
eventually, after
   further optimizations, obtain an efficient evaluation strategy.
   
   This seems like desirable behavior, and consistent with the general 
direction of subquery de-correlation. 
   


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