Fix a correctness issue around referenceless expressions being evaluated as partition filters #4069
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Which Delta project/connector is this regarding?
Description
Fixes a data correctness issue, when non-deterministic expressions without any reference columns are used, such as rand() as a filter on a Delta table. These filters were being evaluated as partition filters and getting double evaluated. This caused a filter such as
rand() < 0.5to filter ~75% of the data (due to being double evaluated) instead of just 50%.Added a feature flag just in case for old behavior
How was this patch tested?
Added a unit test and tested the old behavior as well with a feature flag
Does this PR introduce any user-facing changes?
Filters such as rand() will not be double evaluated anymore