[DRILL-4905] Push down the LIMIT to the parquet reader scan to limit the numbers of records read

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.0
• Fix Version/s: 1.9.0
• Component/s: Storage - Parquet
• Assignee: Padma Penumarthy
• Reporter: Padma Penumarthy
• Reviewer: Rahul Kumar Challapalli
• Created: 26/Sep/16 18:44
• Updated: 08/Nov/16 21:16
• Resolved: 25/Oct/16 01:21

Description

Limit the number of records read from disk by pushing down the limit to parquet reader.

For queries like
select * from <table> limit N;

where N < size of Parquet row group, we are reading 32K/64k rows or entire row group. This needs to be optimized to read only N rows.

Issue Links

• links to: GitHub Pull Request #597