[HIVE-19262] empty array will be saved as NULL by insert into select

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.13.1
• Component/s: File Formats
• Assignee: Unassigned
• Reporter: liupengcheng
• Created: 21/Apr/18 09:19
• Updated: 22/Apr/18 04:37

Description

Data is generated by MR parquet, and the data contains empty list.

When executing the following sql, the emtpy list col of the result is different from the original data.

`insert into table a as select * from b `

>select col1 from a where size(col1) = 0 limit 1;

 []    // will show []

>insert into table b select col1 from a;
>select col1 from b;

 NULL  // will show NULL

I was wondering if we should return the same result as before, and should not change the data saved.