[HIVE-2271] InConsistency between Infomation Document and Actual Behavior for Built In Aggregate Functions(UDAF) Return Type.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 0.5.0, 0.6.0, 0.7.0, 0.7.1
• Component/s: Documentation, Query Processor

Environment

SuSE-Linux-11

• Assignee: Unassigned
• Reporter: Rohith Sharma K S
• Created: 07/Jul/11 12:31
• Updated: 06/Oct/16 12:30
• Resolved: 06/Oct/16 12:30

Description

I followed the Information Document for executing UDAF like MIN(),MAX(),SUM(),AVG() and COUNT() below link.

https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-BuiltinAggregateFunctions%28UDAF%29

Observed mismatch for RETURN TYPE mentioned in Information Document and Actual Behavior.

1.) Return Type for min(colName),max(colName) is mentioned as DOUBLE,but while retrieving it is returning colName DataType passed to Min()/Max().

Ex:
1).create table test(a int,b smallint,c string);
2).select min(a) from test;
3).ResultSet.getMetaData ().getColumnTypeName ( 1 )
Output : int
Expected : double(According to InformationDoc)

2.) Return Type for sum(colName) is mentioned as DOUBLE,but while retrieving it is always returning as BIGINT

Ex:
1).create table test(a int,b smallint,c string);
2).select sum(a) from test;
3).ResultSet.getMetaData ().getColumnTypeName ( 1 )
Output : BIGINT
Expected : double(According to InformationDoc)