ROW Data Types

A ROW data type is an ordered collection of one or more elements, called fields. Each field has a name and a data type. The fields of a ROW are comparable to the columns of a table, but with important differences:
  • A field has no default clause.
  • You cannot define constraints on a field.
  • You can only use fields with row types, not with tables.
Two kinds of ROW data types exist:
  • Named ROW data types are identified by their names.
  • Unnamed ROW data types are identified by their structure.

The structure of an unnamed ROW data type is the number (and the order of data types) of its fields.

No more than 195 columns of the same table can be declared as ROW data types. For more information about ROW data types, see ROW data type, Named and ROW data type, Unnamed.

You can cast between named and unnamed ROW data types; this is described in the HCL OneDB™ Database Design and Implementation Guide.