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Replace Lexicographic Kernels With Row Format #2871

@tustvold

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@tustvold

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

lexsort, lexsort_to_indices, lexicographical_partition_ranges, etc... make use of LexicographicalComparator to compare rows. The branching and dynamic dispatch involved in this comparator is relatively expensive. Converting to the row format first, and comparing these rows has been found to offer significant performance advantages in similar applications - apache/datafusion#3386.

Describe the solution you'd like

We should provide examples, and potentially some utilities if necessary, to use the row format for these use-cases instead. We can then deprecate the lexicographic kernels and eventually remove them

Describe alternatives you've considered

We could leverage the row format within the existing kernels, however, this has a few drawbacks:

  • The additional memory consumption is not necessarily obvious
  • When chaining operators together, e.g. sort then partition, the row format conversion will be performed twice
  • It isn't obvious how process data in batches

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