beliefer opened a new pull request #30419:
URL: https://github.com/apache/spark/pull/30419
### What changes were proposed in this pull request?
`OptimizeWindowFunctions` used to transfer `first` to `nth_value`.
If the window frame is `UNBOUNDED PRECEDING AND CURRENT ROW` or `UNBOUNDED
PRECEDING AND UNBOUNDED FOLLOWING`, `nth_value` has better performance than
`first`.
But the `OptimizeWindowFunctions` need to exclude other window frame.
### Why are the changes needed?
Improve `OptimizeWindowFunctions` to avoid transfer `first` to `nth_value`
if the specified window frame isn't `UNBOUNDED PRECEDING AND CURRENT ROW` or
`UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING`.
### Does this PR introduce _any_ user-facing change?
'No'.
### How was this patch tested?
Jenkins test.
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