Major Description
Spark supports case-sensitivity in columns. Especially, for Struct types, with case sensitive option, the following is supported.
scala> sql("select named_struct('a', 1, 'A', 2).a").show +--------------------------+ |named_struct(a, 1, A, 2).a| +--------------------------+ | 1| +--------------------------+ scala> sql("select named_struct('a', 1, 'A', 2).A").show +--------------------------+ |named_struct(a, 1, A, 2).A| +--------------------------+ | 2| +--------------------------+
And vice versa, with case sensitive `false`, the following is supported.
scala> sql("select named_struct('a', 1).A, named_struct('A', 1).a").show
+--------------------+--------------------+
|named_struct(a, 1).A|named_struct(A, 1).a|
+--------------------+--------------------+
| 1| 1|
+--------------------+--------------------+
This issue aims to support case-insensitive type comparisions in Set operation. Currently, SET operations fail due to case-sensitive type comparision failure .
scala> sql("SELECT struct(1 a) UNION ALL (SELECT struct(2 A))").show org.apache.spark.sql.AnalysisException: Union can only be performed on tables with the compatible column types. struct<A:int> <> struct<a:int> at the first column of the second table;; 'Union :- Project [named_struct(a, 1) AS named_struct(a, 1 AS `a`)#2] : +- OneRowRelation$ +- Project [named_struct(A, 2) AS named_struct(A, 2 AS `A`)#3] +- OneRowRelation$
