[CALCITE-1853] Push Count distinct into Druid when approximate results are acceptable

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.13.0
• Component/s: druid-adapter
• Assignee: Zain Humayun
• Reporter: Zain Humayun
• Created: 20/Jun/17 17:36
• Updated: 27/Feb/24 22:23
• Resolved: 22/Jun/17 16:11

Description

Currently queries such as

select count(distinct "dimension") from "table";

are not pushed into Druid using the cardinality aggregator because it produces an approximate result. There exists a JDBC string parameter called approximateDistinctCount introduced in CALCITE-1587 that lets the user specify whether approximate results are acceptable in count distinct queries, however this parameter is not currently utilized by the Druid adapter.

Issue Links

• is related to: CALCITE-1787 thetaSketch Support for Druid Adapter
• links to: Pull Request