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https://issues.apache.org/jira/browse/PARQUET-787?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ryan Blue updated PARQUET-787:
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Issue Type: Improvement (was: Bug)
> Add a size limit for heap allocations when reading
> --------------------------------------------------
>
> Key: PARQUET-787
> URL: https://issues.apache.org/jira/browse/PARQUET-787
> Project: Parquet
> Issue Type: Improvement
> Components: parquet-mr
> Affects Versions: 1.9.0
> Reporter: Ryan Blue
> Assignee: Ryan Blue
>
> [G1GC allocates humongous objects directly in the old
> generation|https://www.infoq.com/articles/tuning-tips-G1-GC] to avoid
> unnecessary copies, which means that these allocations aren't garbage
> collected until a full GC runs. Humongous objects are objects that are 50% of
> the region size or more. Region size is at most 32MB (see the table for
> [region size from heap
> size|http://product.hubspot.com/blog/g1gc-fundamentals-lessons-from-taming-garbage-collection#Regions]).
> Parquet currently allocates a huge buffer for each contiguous group of column
> chunks, which in many cases is not garbage collected until a full GC. Adding
> a size limit for the allocation size should allow users to break row groups
> across multiple buffers so that buffers get collected when they have been
> read.
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