When archived data is read, the system automatically makes the conversions required by hardware and software changes.

When old archive files are accessed, the Archive Development Kit (ADK) can make allowances for changes to database structures (field types, field lengths, new fields, and deleted fields) after the data was archived and for changes to hardware-dependent storage formats. This is only done during read access. The data in the archive file is not changed. The following items are changed (if necessary) during automatic conversion:

• Database table schema (new and deleted columns)

• Data type of a column

• Column length

• Type of file (ASCII, EBCDIC, and so on)

• Number format (such as the use of the integer format on various hardware platforms)

If database structures in an application have undergone more changes than the ADK can handle (for example, if fields have been moved from one table to another or if one table has been divided into several tables), then a program is provided by the application for the permanent conversion of existing archive files.