alkis opened a new pull request, #248: URL: https://github.com/apache/parquet-format/pull/248
### Incremental parquet metadata improvements This is an alternative proposal to https://github.com/apache/parquet-format/pull/242 which can be executed with minimal changes to parquet readers/writers. Wide schemata (large number of columns) make `FileMetadata` very slow to parse. The majority of the time is spent in parsing thrift `list<>` and `binary` fields. These are notoriously slow to decode because they are variable sized. In this proposal we avoid such fields as much as possible to improve decoding. In addition we allow columns that do not participate in a row group to have their column chunk metadata skipped. ### 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). ### 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 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
