[HIVE-1694] Accelerate GROUP BY execution using indexes

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.7.0
• Fix Version/s: 0.8.0
• Component/s: Indexing, Query Processor
• Hadoop Flags: Reviewed
• Assignee: Prajakta Kalmegh Assign to me
• Reporter: Nikhil Deshpande
• Created: 06/Oct/10 11:07
• Updated: 05/Apr/14 22:16
• Resolved: 13/Sep/11 02:21

Description

The index building patch (Hive-417) is checked into trunk, this JIRA issue tracks supporting indexes in Hive compiler & execution engine for SELECT queries.

This is in ref. to John's comment at

https://issues.apache.org/jira/browse/HIVE-417?focusedCommentId=12884869&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#action_12884869

on creating separate JIRA issue for tracking index usage in optimizer & query execution.

The aim of this effort is to use indexes to accelerate query execution (for certain class of queries). E.g.

• Filters and range scans (already being worked on by He Yongqiang as part of HIVE-417?)
• Joins (index based joins)
• Group By, Order By and other misc cases

The proposal is multi-step:
1. Building index based operators, compiler and execution engine changes
2. Optimizer enhancements (e.g. cost-based optimizer to compare and choose between index scans, full table scans etc.)

This JIRA initially focuses on the first step. This JIRA is expected to hold the information about index based plans & operator implementations for above mentioned cases.

Issue Links

• relates to: HIVE-417 Implement Indexing in Hive
• relates to: HIVE-1803 Implement bitmap indexing in Hive