apache / apache/parquet-java

Vectorized Reader In Parquet

Open
#1,657 24 comments 0 reactions 0 assignees View on GitHub
Component: Java Component: Parquet Priority: Major Type: enhancement
Dominant language
Java
Stars
3.1k
Forks
1.6k
Avg merge
3d 12h
Merged PRs (30d)
33

Description

Vectorized Query Execution could have big performance improvement for SQL engines like Hive, Drill, and Presto. Instead of processing one row at a time, Vectorized Query Execution could streamline operations by processing a batch of rows at a time. Within one batch, each column is represented as a vector of a primitive data type. SQL engines could apply predicates very efficiently on these vectors, avoiding a single row going through all the operators before the next row can be processed.
As an efficient columnar data representation, it would be nice if Parquet could support Vectorized APIs, so that all SQL engines could read vectors from Parquet files, and do vectorized execution for Parquet File Format.

Detail proposal:
https://gist.github.com/zhenxiao/2728ce4fe0a7be2d3b30

**Reporter**: [Zhenxiao Luo](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=zhenxiao) / @zhenxiao
**Assignee**: [Zhenxiao Luo](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=zhenxiao) / @zhenxiao
#### Subtasks:
- [ ] [[Vectorized Reader] Support Complex Types (Map, Array, Struct) in Parquet Vectorized Reader](https://github.com/apache/parquet-java/issues/1824)
- [ ] [[Vectorized Reader] ColumnVector length should be in terms of rows, not DataPages](https://github.com/apache/parquet-java/issues/1439)
- [ ] [[Vectorized Reader] Make sure all encodings work in Parquet Vectorized Reader](https://github.com/apache/parquet-java/issues/1825)
- [ ] [[Vectorized Reader] Lazy Load in Vectorized Reader](https://github.com/apache/parquet-java/issues/1826)
- [ ] [[Vectorized Reader] Lazy Decoding in Vectorized Reader](https://github.com/apache/parquet-java/issues/1827)
- [ ] [[Vectorized Reader] Add Testcases/Benchmarks for ParquetVectorizedReader](https://github.com/apache/parquet-java/issues/1828)
- [ ] [[Vectorized Reader] Add attributes in ColumnVector and RowBatch](https://github.com/apache/parquet-java/issues/1852)
#### Related issues:
- [Improve Parquet Vectorization](https://issues.apache.org/jira/browse/HIVE-8128) (is related to)
#### Original Issue Attachments:
- [ParquetInPresto.pdf](https://issues.apache.org/jira/secure/attachment/12684592/ParquetInPresto.pdf)
- [Parquet-Vectorized-APIs.pdf](https://issues.apache.org/jira/secure/attachment/12684393/Parquet-Vectorized-APIs.pdf)

**Note**: *This issue was originally created as [PARQUET-131](https://issues.apache.org/jira/browse/PARQUET-131). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the linked vectorized API proposal and review the listed subtasks for the current scope, especially complex types, encodings, lazy loading, and benchmarks. Done means Parquet exposes vectorized reading support suitable for SQL engines, with the listed reader behavior and test or benchmark coverage addressed.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
data-engineering
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.