new SchemaAliasVisitor(this).visit();
new ScalarVisitor(this, pigContext, scope).visit();
// ImplicitSplitInsertVisitor has to be called before
// DuplicateForEachColumnRewriteVisitor. Detail at pig-1766
new ImplicitSplitInsertVisitor(this).visit();
// DuplicateForEachColumnRewriteVisitor should be before
// TypeCheckingRelVisitor which does resetSchema/getSchema
// heavily
new DuplicateForEachColumnRewriteVisitor(this).visit();