INTERNALLENGTH Modifier

The INTERNALLENGTH modifier specifies the storage size that is required for the opaque data type as fixed length or varying length.

Fixed-Length Opaque Types

A fixed-length opaque type has an internal structure of fixed size. To create a fixed-length opaque type, specify the size of the internal structure, in bytes, for the INTERNALLENGTH modifier. The next example creates a fixed-length opaque type called fixlen_typ and allocates 8 bytes for storing this data type.

CREATE OPAQUE TYPE fixlen_typ(INTERNALLENGTH=8, CANNOTHASH)

Varying-Length Opaque Types

A varying-length opaque type has an internal structure whose size might vary from one value to another. For example, the internal structure of an opaque data type might hold the actual value of a string up to a certain size, but beyond this size it might use an LO-pointer to a CLOB to hold the value.

To create a varying-length opaque data type, use the VARIABLE keyword with the INTERNALLENGTH modifier. The following statement creates a variable-length opaque data type called varlen_typ:

CREATE OPAQUE TYPE varlen_typ
(INTERNALLENGTH=VARIABLE, MAXLEN=1024)