These topics discuss how to change the database file
descriptions and attributes. Considerations for changing fields in a file
description are also included.
Effects of changing fields in a file description
The system uses the information in the record format description to determine the level identifier. Changes to the fields in a file description cause the level identifier to change. Changes in key fields or select/omit fields might cause unexpected results in programs using the new access path.
Change a physical file description and attributes
Sometimes when you make a change to a physical file description and then re-create the file, the level identifier can change. If the level identifier changes, you can either compile the program again or avoid recompiling using a logical file.
Change a logical file description and attributes
As a general rule, when you make changes to a logical file, which causes a change to the level identifier (for example, adding a new field, deleting a field, or changing the length of a field), it is strongly recommended that you recompile the program that uses the logical file.