You are viewing a plain text version of this content. The canonical link for it is here.
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:
-----------------------------------

             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


--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira