Opaque data types

An opaque data type is a C structure, which the database server does not interpret. Instead, the database server calls internal support routines that you provide to manipulate the structure. Opaque data types have an internal structure made up of members. Members can be built-in data types or other extended data types. Users cannot access the values of individual members from SQL; however, you can create accessor methods to manipulate opaque data type members.

For more information, see the Informix® User-Defined Routines and Data Types Developer's Guide.