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Improve performance of InternalParquetRecordReader (1%)

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#3,226 0 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
55/100
Issue type
Feature
Clarity
Clearly specified
Activity status
Stale
Tech stack
java

Research direction

Start in parquet-hadoop/src/main/java/org/apache/parquet/hadoop/InternalParquetRecordReader.java at the LongStream around line 323, then review the linked parquet-rowindexiterator benchmark project. Compare the reader's current iteration with the benchmark's Long Iterator approach; done means the reader avoids the reported LongStream overhead while preserving row-index iteration behavior.

Written by the indexing model from the issue text.

Description

Type: enhancement
Describe the enhancement requested

Profiling the load of a Parquet file with Java Mission Control, I've noticed that InternalParquetRecordReader LongStream consumes relevant amount of time.

This LongStream can be replaced with a simpler Long Iterator that iterates from 0 to pages.getRowCount().

To measure the overhead I've created a test project that overwrites InternalParquetRecordReader implementation with a Long Iterator: https://github.com/jerolba/parquet-rowindexiterator

The execution time is sensitive to the context of the JVM, but running the benchmark multiple times shows that LongStream is slower than LongIterator, between 1% and 4% depending on the run.

Component(s)

No response

Dominant language
Java
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Avg merge
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Merged PRs (30d)
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