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ASF GitHub Bot commented on PARQUET-2366: ----------------------------------------- ConeyLiu opened a new pull request, #1174: URL: https://github.com/apache/parquet-mr/pull/1174 Make sure you have checked _all_ steps below. ### Jira - [ ] My PR addresses the following [Parquet Jira](https://issues.apache.org/jira/browse/PARQUET/) issues and references them in the PR title. For example, "PARQUET-1234: My Parquet PR" - https://issues.apache.org/jira/browse/PARQUET-XXX - In case you are adding a dependency, check if the license complies with the [ASF 3rd Party License Policy](https://www.apache.org/legal/resolved.html#category-x). ### Tests - [ ] My PR adds the following unit tests __OR__ does not need testing for this extremely good reason: ### Commits - [ ] My commits all reference Jira issues in their subject lines. In addition, my commits follow the guidelines from "[How to write a good git commit message](http://chris.beams.io/posts/git-commit/)": 1. Subject is separated from body by a blank line 1. Subject is limited to 50 characters (not including Jira issue reference) 1. Subject does not end with a period 1. Subject uses the imperative mood ("add", not "adding") 1. Body wraps at 72 characters 1. Body explains "what" and "why", not "how" ### Documentation - [ ] In case of new functionality, my PR adds documentation that describes how to use it. - All the public functions and the classes in the PR contain Javadoc that explain what it does The `ColunIndex`, `OffsetIndex`, and `BloomFilter` are stored at the end of the file. We need to randomly seek 4 times when rewriting a column chunk. We found this could impact the rewrite performance heavily for files with a number of columns(~1000). In this PR, we read the `ColumnIndex`, `OffsetIndex`, and `BloomFilter` into a cache to avoid the random seek. We got about 60 times performance improvement in production environments for the files with about one thousand columns. > Optimize random seek during rewriting > ------------------------------------- > > Key: PARQUET-2366 > URL: https://issues.apache.org/jira/browse/PARQUET-2366 > Project: Parquet > Issue Type: Improvement > Reporter: Xianyang Liu > Priority: Major > > The `ColunIndex`, `OffsetIndex`, and `BloomFilter` are stored at the end of > the file. We need to randomly seek 4 times when rewriting a column chunk. We > found this could impact the rewrite performance heavily for files with a > number of columns(~1000). In this PR, we read the `ColumnIndex`, > `OffsetIndex`, and `BloomFilter` into a cache to avoid the random seek. We > got about 60 times performance improvement in production environments for the > files with about one thousand columns. -- This message was sent by Atlassian Jira (v8.20.10#820010)