[HIVE-1343] add an interface in RCFile to support concatenation of two files without (de)compression

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.6.0
• Fix Version/s: 0.8.0
• Component/s: Serializers/Deserializers
• Assignee: He Yongqiang
• Reporter: Ning Zhang
• Created: 13/May/10 23:01
• Updated: 24/Jul/14 22:32
• Resolved: 21/Apr/11 00:05

Description

If two files are concatenated, we need to read each record in these files and write them back to the destination file. The IO cost is mostly unavoidable due to the lack of append functionality in HDFS. However the CPU cost could be significantly reduced by avoiding compression and decompression of the files.

The File Format layer should provide API that implement the block-level concatenation.

Issue Links

• relates to: HIVE-1950 Block merge for RCFile
• relates to: HIVE-7509 Fast stripe level merging for ORC