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Posted to dev@hive.apache.org by "Owen O'Malley (JIRA)" <ji...@apache.org> on 2013/01/09 17:20:13 UTC
[jira] [Created] (HIVE-3874) Create a new Optimized Row Columnar
file format for Hive
Owen O'Malley created HIVE-3874:
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Summary: Create a new Optimized Row Columnar file format for Hive
Key: HIVE-3874
URL: https://issues.apache.org/jira/browse/HIVE-3874
Project: Hive
Issue Type: Improvement
Components: Serializers/Deserializers
Reporter: Owen O'Malley
Assignee: Owen O'Malley
There are several limitations of the current RC File format that I'd like to address by creating a new format:
* each column value is stored as a binary blob, which means:
** the entire column value must be read, decompressed, and deserialized
** the file format can't use smarter type-specific compression
** push down filters can't be evaluated
* the start of each row group needs to be found by scanning
* user metadata can only be added to the file when the file is created
* the file doesn't store the number of rows per a file or row group
* there is no mechanism for seeking to a particular row number, which is required for external indexes.
* there is no mechanism for storing light weight indexes within the file to enable push-down filters to skip entire row groups.
* the type of the rows aren't stored in the file
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