[SPARK-34199] Block `count(table.*)` to follow ANSI standard and other SQL engines

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.0
• Fix Version/s: 3.2.0
• Component/s: SQL
• Assignee: Linhong Liu
• Reporter: Linhong Liu
• Created: 22/Jan/21 03:51
• Updated: 02/Feb/21 07:50
• Resolved: 02/Feb/21 07:50

Description

In spark, the count(table.*) may cause very weird result, for example:

select count from (select 1 as a, null as b) t;

output: 1

select count(t.*) from (select 1 as a, null as b) t;

output: 0

 

After checking the ANSI standard, count is always treated as count(1) while count(t.*) is not allowed. What's more, this is also not allowed by common databases, e.g. MySQL, oracle.

Issue Links

• links to: [Github] Pull Request #31286 (linhongliu-db)