[PIG-1654] Pig should check schema alias duplication at any levels.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.9.0
• Assignee: Xuefu Zhang
• Reporter: Xuefu Zhang
• Created: 28/Sep/10 23:02
• Updated: 26/Jul/13 08:26
• Resolved: 15/Mar/11 18:35

Description

The following script appears valid to Pig but it shouldn't:

A = load 'file' as (a:tuple( u:int, u:bytearray, w:long), b:int, c:chararray);
dump A;

Pig tries to launch map/reduce jobs for this.

However, for the following script, Pig correctly reports error message:

A = load 'file' as (a:int, a:long, c:bytearray);
dump A;

Error message is:
2010-09-28 15:53:37,390 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1108: Duplicate schema alias: b in "A"

Thus, Pig only checks alias duplication at the top level, which is confirmed by looking at the code. The right behavior is that the same check should be applied at all levels.

This should be addressed in the new parser.

Issue Links

• is related to: PIG-3397 Strange plan validation issue with duplicated schema