Predefined Data Types

The database server provides the predefined data types, just as it provides the fundamental data types. However, the predefined data types have certain characteristics in common with the extended data types.

BOOLEAN and LVARCHAR Data Types

BOOLEAN and LVARCHAR data types behave like built-in data types except that the system catalog tables define them as extended data types.

For more information, refer to Choosing Data Types and to the system catalog tables in the IBM Informix: Guide to SQL Reference.

BLOB and CLOB Data Types

The BLOB and CLOB data types are not fundamental data types because you can randomly access data from within the BLOB or CLOB. You can create a table with BLOB and CLOB columns, but you cannot insert data directly into the column. You must use functions to insert and manipulate the data.

For more information, see Smart Large Objects.

Other Predefined Data Types

With the exception of BLOB, BOOLEAN, CLOB, and LVARCHAR, the predefined data types usually do not appear as data types for the columns of a table. Instead, the predefined data types are used with the functions associated with complex and user-defined data types and user-defined routines. The following table lists the remaining predefined data types.

For more information about these predefined data types, refer to IBM Informix: User-Defined Routines and Data Types Developer's Guide.