[IOTDB-1383] Group By Level Query Process Improvement

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Core/Engine
• Assignee: Unassigned
• Reporter: Yuan Tian
• Created: 20/May/21 01:14
• Updated: 20/May/21 01:14

Description

Currently, the intermediate dataset is too large, we need to calculate all the aggregation result of each series, put them all in the memory and then calculate the final result.

Actually, we can iteratively compute the result set to save the mermory footprint.

Also, we need to reestimate the size of group by level dataset.