Refactor Builtin Window Function Implementation #4441
Merged
+122
−164
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Which issue does this PR close?
Closes #4440.
Rationale for this change
Handling of the Builtin Window Functions (such as
ROW_NUMBER
,FIRST_VALUE
, etc.) are quite different than accumulators (such asSUM
,AVG
, etc.) even though they have significant commonalities. We can increase readability if we make their implementation similar in spirit; and we can increase code reuse in this way too. This PR changes thePartitionEvaluator
trait such that it resembles theAccumulator
trait.What changes are included in this PR?
The
create_evaluator
method ofBuiltInWindowFunctionExpr
no longer takes a record batch during creation. Instead; when we are doing evaluation, we pass the relevant batch section to theevaluate
method of thePartitionEvaluator
trait.Are these changes tested?
N.A (Existing tests should work after refactor)
Are there any user-facing changes?