From now, we don't support type derivation for array function's arguments.
So that the cases below will return wrong values or even cause be core.
mysql> select array_union([1],[10000000]);
+----------------------------------------+
| array_union(ARRAY(1), ARRAY(10000000)) |
+----------------------------------------+
| [1, -128] |
+----------------------------------------+
1 row in set (0.03 sec)
mysql> select array_union([NULL],[1]);
ERROR 1105 (HY000): RpcException, msg: io.grpc.StatusRuntimeException: UNAVAILABLE: Network closed for unknown reason
mysql> select array_union([],[1]);
ERROR 1105 (HY000): RpcException, msg: io.grpc.StatusRuntimeException: UNAVAILABLE: Network closed for unknown reason
This commit make a small fix to derivate the argument types of the array function
1、 For null type in arguments, cast the null type to boolean type, because null type should not be seen in be.
2、For different types in arguments, cast all arguments type to their compatible type.
177e82bdab