Hi, A schema in Pig (LogicalSchema.java) is defined as an array list of LogicalFieldSchema whose class members are: - String alias - byte type - long uid - LogicalSchema schema
I am wondering why is LogicalFieldShema containing a LogicalSchema member? My guess so far is that perhaps there's a subschema used by some operators? I tried to figure out which operators might be using it and categorized the main ones as follow: ==> SCHEMA IS DEFINED BY INPUT SCHEMA ONLY LOAD DISTINCT FILTER ORDER BY SPLIT ==> SCHEMA IS DEFINED BY THE LIST OF "AS" IN THE FOREACH STATEMENT FOREACH ==> IF SCHEMA CAN BE DEFINED (SAME LENGTH AND CASTABLE) OR UNKNOWN SCHEMA UNION ==> SCHEMA IS DEFINED BY THE CONCATENATION OF THE TWO INPUT SCHEMAS (+ ADDING THE ALIAS TO THE FIELD NAME x ==> A::x) JOIN *Are the two inputs here considered subschemas?* ==> SCHEMA: (key_to_order_by, bag) GROUP Thanks, Keren -- Keren Ouaknine Web: www.kereno.com
