[HIVE-819] Add lazy decompress ability to RCFile

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.5.0
• Component/s: Query Processor, Serializers/Deserializers
• Hadoop Flags: Reviewed
• Assignee: He Yongqiang
• Reporter: He Yongqiang
• Created: 09/Sep/09 03:42
• Updated: 17/Dec/11 00:06
• Resolved: 02/Nov/09 19:09

Description

This is especially useful for a filter scanning.
For example, for query 'select a, b, c from table_rc_lazydecompress where a>1;' we only need to decompress the block data of b,c columns when one row's column 'a' in that block satisfies the filter condition.