Handling Extended Data Types (IDS)

The extensible data type system of Dynamic Server allows users to define new data types and the behavior of these new data types to the database server. This section explains how these types are handled in GLS processing. See also IBM Informix: User-Defined Routines and Data Types Developer's Guide.

Opaque Data Types

An opaque data type is fully encapsulated to client applications; that is, its internal structure is not known to the database server. Therefore, the database server cannot automatically perform locale-specific tasks such as code-set conversion for opaque types. All GLS processing (code-set conversion, localized collation order, end-user formats, and so on) must be performed in the opaque-type support functions.

When you create an opaque data type, you can write the support functions as C UDRs that can handle any locale-sensitive data. For more information, see Locale-Sensitive Data in an Opaque Data Type.

Complex Data Types

Dynamic Server also supports complex data types:

• Collection data types: SET, MULTISET, and LIST
• Row data types: named ROW types and unnamed ROW types

Any of these data types can have members with character, time, or numeric data types. The database server can still handle the GLS processing for these data types when they are part of a complex data type.

Distinct Data Types

A distinct data type has the same internal storage representation as its source type but has a different name. Its source type can be an opaque or built-in type, a named ROW type, or another distinct data type. Dynamic Server handles GLS considerations for a distinct type as it would for the source type.