[HIVE-21876] Documentation : collect_list documentation does not mention it silently ignores nulls

• Type: Bug
• Status: Open
• Priority: Trivial
• Resolution: Unresolved
• Component/s: Documentation

Environment

select version()

_c0▼
2.1.0.2.6.5.1050-37 rb49a1217fdf463c41661ec6512348ff9ef4706a9

• Assignee: Unassigned
• Reporter: Guillaume Xavier Taillon
• Created: 14/Jun/19 16:58
• Updated: 14/Jun/19 16:58

Description

Documentation at 

https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-Built-inAggregateFunctions(UDAF)

For collect_list is currently only 

array

collect_list(col)

Returns a list of objects with duplicates. (As of Hive 0.13.0.)

However it should mention that nulls are not captured, at least on Hive 2.1

select collect_list(v) from (
select 1 as v
union all select null as v
union all select 3 as v
) t

Result

_c0

[1,3]