[IMPALA-2250] Make multiple COUNT(DISTINCT) message state workarounds

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Impala 2.2.4
• Fix Version/s: Impala 2.11.0
• Component/s: Frontend
• Labels: newbie usability
• Target Version: Product Backlog
• Assignee: Jin Chul Kim
• Reporter: John Russell
• Created: 25/Aug/15 21:07
• Updated: 23/Nov/17 02:16
• Resolved: 23/Nov/17 02:16

Description

The message for a query with multiple COUNT(DISTINCT) currently looks like:

[localhost:21000] > select count(distinct x), count(distinct y) from t1;
ERROR: AnalysisException: all DISTINCT aggregate functions need to have the same set of parameters as count(DISTINCT x); deviating function: count(DISTINCT y)

How about adding an INFO message after the error saying something like:

INFO: If estimated counts are OK, replace COUNT(DISTINCT) with NDV(). Enable the APPX_COUNT_DISTINCT query option to perform this rewrite automatically.