Create the internal structure in C

The internal structure of an opaque data type is a C data structure. For the internal structure, use the C typedefs that the DataBlade® API supplies for those fields whose size might vary by platform. Use of these typedefs, such as mi_integer and mi_float, improves the portability of the opaque data type. For more information about these data types, see the HCL OneDB™ DataBlade API Programmer's Guide.

When you create the internal structure, consider the following impacts of the size of this structure:
  • The final structure size of the new opaque data type
  • The alignment in memory of the opaque data type
  • The method for passing the opaque data type to UDRs

You provide this information when you create the opaque data type with the CREATE OPAQUE TYPE statement.