Transferring the Database Structure

You can only use the Data Structure and Transfer utility (RECASTDB) when the source and target databases reside on the same system.

When you transfer the structure:

• If the target database is an older version of the source database, the data independence mechanism upgrades the existing data

• The source database structure completely replaces the structure of the target database

  After transferring the structure, run the database integrity checker against the database to determine what, if any, action you need to take. For example, if the data independence mechanism is invoked by the structure transfer, you will be advised to run a database reorganisation to rebuild the data file.

To transfer the database structure:

1. On the DP4 System menu, select the Database Management option. The Database Structure Management menu appears

2. On the Database Structure Management menu, select the Transfer structure/data option

3. Enter the name of the source database

4. Enter the name of the target database. The Data Structure and Data Transfer menu appears:
   

   Two options on this menu are concerned with structure transfer:

   • Option 1 - Structure transfer replaces the structure of the target database with that of the source database

   • Option 7 - Options specifies whether QA Build source code and data dictionary information is transferred. This should normally be transferred unless:

     • You want to deliver a runtime-only system that does not allow users to edit QA Build programs
     • You want to speed up the structure transfer and know that the data dictionary information is identical in both databases
       
       

5. Select option 1 - Structure transfer . The System Data Options screen is displayed:
   
   These options let you select the additional information you would like the transfer utility to copy to the target database. There are two input columns, as follows

   Transfer? enables the type of additional information to transfer. Disable all the options to transfer just the database structure

   Delete data not on source? enables an option to delete data, for example Report Writer programs, on the target database that is not present on the source. Disable an option to retain existing target data that is not on the source

   As an alternative, be aware that there are specific, more powerful utilities for transferring additional system data. For example, MAPEDIT and MAPPOST transfer maps and QABUTIL transfers QA Build programs and their maps

6. Make your selections and press the <Tab> key. DP4 transfers the database structure. Messages are displayed which show the progress of the operation. The transfer completes and a message appears advising you of what action to take:
   

7. Press <Enter> to return to the Data Structure and Data Transfer menu

If the database independence mechanism has been invoked due to the structure transfer, run a database reorganisation. To see the action recommended by DP4, run the Database Integrity Checker, select Option 1 - Status display and examine the Database status field.