[CARBONDATA-1526] 10. Handle compaction in aggregation tables.

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0
• Assignee: Kunal Kapoor
• Reporter: Ravindra Pesala
• Created: 27/Sep/17 10:25
• Updated: 07/Dec/17 15:52
• Resolved: 07/Dec/17 15:52

Description

User can trigger compaction on pre-aggregate table directly, it will further merge the segments inside pre-aggregation table. To do that, use ALTER TABLE COMPACT command on the pre-aggregate table just like the main table.

For implementation, there are two kinds of implementation for compaction.
1. Mergable pre-aggregate tables: if aggregate functions are count, max, min, sum, avg, the pre-aggregate table segments can be merged directly without re-computing it.
2. Non-mergable pre-aggregate tables: if aggregate function include distinct_count, it needs to re-compute when doing compaction on pre-aggregate table.

Issue Links

• links to: GitHub Pull Request #1605