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https://issues.apache.org/jira/browse/PARQUET-1698?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17014647#comment-17014647
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David Li commented on PARQUET-1698:
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[~wesm] agreed, this optimization can be generic over the storage backend, and
probably even the format (if other formats contain the necessary metadata). The
logical place to me seems like the datasets project, no?
> [C++] Add reader option to pre-buffer entire serialized row group into memory
> -----------------------------------------------------------------------------
>
> Key: PARQUET-1698
> URL: https://issues.apache.org/jira/browse/PARQUET-1698
> Project: Parquet
> Issue Type: Improvement
> Components: parquet-cpp
> Reporter: Wes McKinney
> Assignee: Zherui Cao
> Priority: Major
> Labels: pull-request-available
> Fix For: cpp-1.6.0
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> In some scenarios (example: reading datasets from Amazon S3), reading columns
> independently and allowing unbridled {{Read}} calls to the underlying file
> handle can yield suboptimal performance. In such cases, it may be preferable
> to first read the entire serialized row group into memory then deserialize
> the constituent columns from this
> Note that such an option would not be appropriate as a default behavior for
> all file handle types since low-selectivity reads (example: reading only 3
> columns out of a file with 100 columns) will be suboptimal in some cases. I
> think it would be better for "high latency" file systems to opt into this
> option
> cc [~fsaintjacques] [~bkietz] [~apitrou]
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