The column defined as an identity column must be an arithmetic and exact data type, for example SMALLINT, INTEGER, BIGINT, or DECIMAL, where a scale of zero can be used.
An identity column has the following characteristics: Oracle always maps identity columns to AUTO INCREMENT columns.
A tablespace is created from one or more datafiles.
Datafiles are files in the file system or an area of disk space specified by a device.
The size of a tablespace is determined by the amount of disk space allocated to it.Each tablespace is made up of one or more data files. For more information about the IBM DB2 schema types that do not have a direct mapping in Oracle, see "Design Considerations".Table 2-1 lists the similarities and differences between the schema objects in the two databases, and specifies if SQL Developer supports the migration of these schema objects. Some Oracle reserved words are valid object or column names in IBM DB2.Table 2-2 summarizes the delete integrity constraint mappings between Oracle and IBM DB2, and specifies if SQL Developer supports the migration of these clauses.In IBM DB2 each table is assigned to a table space that contains the primary data for that table.Each table space consists of a collection of containers, each of which is a directory either in the file system, physical file, or device, such as a hard disk.