[DRILL-5065] Optimize count(*) queries on MapR-DB JSON Tables

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.9.0
• Fix Version/s: 1.10.0
• Component/s: Storage - MapRDB
• Labels: ready-to-commit

Environment

Clusters with MapR v5.2.0 and above

• Assignee: Smidth Panchamia
• Reporter: Abhishek Girish
• Reviewer: Abhishek Girish
• Created: 23/Nov/16 19:32
• Updated: 10/Apr/17 17:32
• Resolved: 13/Dec/16 00:47

Description

The JSON FileReader optimizes count(* ) queries, by only counting the number of records in the files and discarding the data. This makes the query execution faster & efficient.

We need a similar feature in the MapR format plugin (maprdb) to optimize _id only projection & count(* ) queries on MapR-DB JSON Tables.

Issue Links

• links to: GitHub Pull Request #667
• links to: GitHub Pull Request #670
• links to: GitHub Pull Request #677
• links to: GitHub Pull Request #678