tustvold opened a new pull request, #4943:
URL: https://github.com/apache/arrow-rs/pull/4943
# Which issue does this PR close?
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Closes #4921
# Rationale for this change
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The parquet specification, especially before version 2, did not make it
especially clear that records should not be split across pages, and prior to
https://github.com/apache/arrow-rs/pull/4327 the Rust writer would do this in
certain situations.
As a result https://github.com/apache/arrow-rs/pull/4376 attempted to not
assume page boundaries delimit records, and instead only relied on row group
boundaries delimiting records.
Unfortunately this logic is incomplete:
* When reading or skipping the last record of a page, this record count will
not be "counted", if the next page is then skipped entirely, the counts get out
of sync with this record never actually accounted for
* When using the offset index to prune IO the reader tries to read pages
beyond those necessary for the RowSelection, if a RowSelector ends on a page
boundary
# What changes are included in this PR?
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This PR removes the workarounds, and simply assumes pages delimit records.
# Are there any user-facing changes?
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