fixed size

An opaque data type can have a fixed size that is determined by the sum of the sizes of the data structures within the opaque data type. The maximum size is 32 KB.

Alternatively, an opaque data type can have a variable size if one of its internal data structures does not have a fixed size. Typically, variable data structures are smart large objects or other opaque data types. Variable-length data structures can have a maximum size. Variable-length opaque data types are treated as bit-varying types.