Changing database file descriptions and attributes

 

Sometimes you might change the descriptions or attributes of a database file by adding, changing, or deleting a field.

• 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.

• Changing 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.

• Changing a logical file description and attributes
  As a general rule, when your changes to a logical file cause a change to the level identifier (for example, adding a new field, deleting a field, or changing the length of a field), recompile the program that uses the logical file.

 

Parent topic:

Managing database files