findepi commented on issue #17401:
URL: https://github.com/apache/datafusion/issues/17401#issuecomment-3252697480

   Some code pieces with seemingly exponential complexity
   
   - 
https://github.com/apache/datafusion/blob/a5c242c21443e4881e6843f754493ab02238b655/datafusion/physical-plan/src/windows/mod.rs#L375-L376
     - for each of N input expressions, `sort_options_resolving_constant` 
returns pair of values (N pairs)
        then `multi_cartesian_product` calculates cartesian product of these 
pairs, 2^N combinations
   - 
https://github.com/apache/datafusion/blob/a5c242c21443e4881e6843f754493ab02238b655/datafusion/physical-plan/src/windows/mod.rs#L469-L470
      - looks same as above
   
   However, every usage of `multi_cartesian_product` looks suspicious. 
   For example, this one looks also dangerous, just not related to window 
functions
   
https://github.com/apache/datafusion/blob/9e062dfb41efbf817e6f0be5bb4e238f8c9ec93c/datafusion/expr-common/src/signature.rs#L551


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