[HIVE-2050] batch processing partition pruning process

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8.0
• Component/s: Metastore, Query Processor
• Labels: PartitionPruner
• Hadoop Flags: Reviewed
• Assignee: Ning Zhang
• Reporter: Ning Zhang
• Created: 11/Mar/11 20:38
• Updated: 20/Aug/12 21:48
• Resolved: 30/Mar/11 01:00

Description

For partition predicates that cannot be pushed down to JDO filtering (HIVE-2049), we should fall back to the old approach of listing all partition names first and use Hive's expression evaluation engine to select the correct partitions. Then the partition pruner should hand Hive a list of partition names and return a list of Partition Object (this should be added to the Hive API).

A possible optimization is that the the partition pruner should give Hive a set of ranges of partition names (say [ts=01, ts=11], [ts=20, ts=24]), and the JDO query should be formulated as range queries. Range queries are possible because the first step list all partition names in sorted order. It's easy to come up with a range and it is guaranteed that the JDO range query results should be equivalent to the query with a list of partition names.