[HIVE-759] add hive.intermediate.compression.codec option

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.5.0
• Component/s: Query Processor
• Labels: compression
• Hadoop Flags: Reviewed
• Release Note: HIVE-759. Add "hive.intermediate.compression.codec/type" option. (Yongqiang He via zshao)
• Assignee: He Yongqiang
• Reporter: Zheng Shao
• Created: 16/Aug/09 00:21
• Updated: 17/Dec/11 00:05
• Resolved: 18/Aug/09 17:37

Description

Hive uses the jobconf compression codec for all map-reduce jobs. This includes both mapred.map.output.compression.codec and mapred.output.compression.codec.

In some cases, we want to distinguish between the codec used for intermediate map-reduce jobs (that produces intermediate data between jobs) and the final map-reduce jobs (that produces data stored in tables).

For intermediate data, lzo might be a better fit because it's much faster; for final data, gzip might be a better fit because it saves disk spaces.

We should introduce two new options:

hive.intermediate.compression.codec=org.apache.hadoop.io.compress.LzoCodec
hive.intermediate.compression.type=BLOCK

And use these 2 options to override the mapred.output.compression.* in the FileSinkOperator that produces intermediate data.

Note that it's possible that a single map-reduce job may have 2 FileSInkOperators: one produces intermediate data, and one produces final data. So we need to add a flag to fileSinkDesc for that.