Major Description
The semantics of * is not consistent in PIG. The use of * with generate results in the all the columns of the record being flattened. However, the use of * as an input to a UDF results in a tuple (wrapped in another tuple). For consistency, * should always result in all the columns of the record (i.e., flattened). The use of * occurs in:
1. Foreach generate: E.g.: foreach input generate *;
2. Input to UDFs: E.g. foreach input generate myUDF
;
3. Order by: E.g.: order input by *;
4. (Co)Group: E.g.: group a by *; cogroup a by *, b by *;
In terms of implementation, this involves rolling back the fix introduced in PIG-597 and fixing the following builtin UDFs:
1. ARITY - Should return the size of the input tuple instead of extracting the first column of the input tuple
2. SIZE - Should return the size of the input tuple instead of extracting the first column of the input tuple