Extracts Generator from the projectList of a Project operator and create Generate
operator under Project.
This rule will throw AnalysisException for following cases:
1. Generator is nested in expressions, e.g. SELECT explode(list) + 1 FROM tbl
2. more than one Generator is found in projectList,
e.g. SELECT explode(list), explode(list) FROM tbl
3. Generator is found in other operators that are not Project or Generate,
e.g. SELECT * FROM tbl SORT BY explode(list)
Extracts Generator from the projectList of a Project operator and create Generate operator under Project.
This rule will throw AnalysisException for following cases: 1. Generator is nested in expressions, e.g.
SELECT explode(list) + 1 FROM tbl
2. more than one Generator is found in projectList, e.g.SELECT explode(list), explode(list) FROM tbl
3. Generator is found in other operators that are not Project or Generate, e.g.SELECT * FROM tbl SORT BY explode(list)