Richard Ding reassigned PIG-847:

    Assignee: Richard Ding

> Setting twoLevelAccessRequired field in a bag schema should not be required 
> to access fields in the tuples of the bag
> ---------------------------------------------------------------------------------------------------------------------
>                 Key: PIG-847
>                 URL: https://issues.apache.org/jira/browse/PIG-847
>             Project: Pig
>          Issue Type: Improvement
>    Affects Versions: 0.2.1
>            Reporter: Pradeep Kamath
>            Assignee: Richard Ding
> Currently Pig interprets the result type of a relation as a bag. However the 
> schema of the relation directly contains the schema describing the fields in 
> the tuples for the relation. However when a udf wants to return a bag or if 
> there is a bag in input data or if the user creates a bag constant, the 
> schema of the bag has one field schema which is that of the tuple. The 
> Tuple's schema has the types of the fields. To be able to access the fields 
> from the bag directly in such a case by using something like 
> <bagname>.<fieldname> or <bag>.<fieldposition>, the schema of the bag should 
> have the twoLevelAccess set to true so that pig's type system can get 
> traverse the tuple schema and get to the field in question. This is confusing 
> - we should try and see if we can avoid needing this extra flag. A possible 
> solution is to treat bags the same way - whether they represent relations or 
> real bags. Another way is to introduce a special "relation" datatype for the 
> result type of a relation and bag type would be used only for true bags. In 
> this case, we would always need bag schema to have a tuple schema which would 
> describe the fields. 

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