[CALCITE-6008] ARRAY_AGG should returns ARRAY NULL when there's no input rows

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.35.0
• Fix Version/s: 1.38.0
• Labels: pull-request-available
• External issue ID: CALCITE-4335
• Assignee: jiabao.sun
• Reporter: jiabao.sun
• Created: 16/Sep/23 10:31
• Updated: 17/Oct/24 22:41
• Resolved: 17/Oct/24 22:41

Description

ARRAY_AGG in BigQuery and Postgres returns NULL if there are zero input rows or expression evaluates to NULL for all rows.
However, it will return `ARRAY<arg0> NOT NULL` in the return type of the function definition.

https://cloud.google.com/bigquery/docs/reference/standard-sql/aggregate_functions#array_agg
https://www.postgresql.org/docs/8.4/functions-aggregate.html

Issue Links

• links to: GitHub Pull Request #3430