11.14 Some Database Design Considerations

Logical data modeling requires a different mindset to traditional database design. The training of people to understand logical data modeling is essential.

MIS staff with limited program coding experience cannot be expected to take on the data modeling component of a project without the necessary training and time to fully develop their experience and skills in small test cases.

Never commence your first data modeling project on a large system. Gain skills and experience in small systems and test cases before attempting to take on a large system.

Minimize the number of logical views. File index maintenance is one of the largest machine resource users. What appears to be one I/O in your program may actually involve many hundreds of disk accesses. Investigate OPNQRYF for rarely used access paths.

Investigate using the IBM i High Speed Table facility to allow faster access to read only validation/decode tables. For more information refer to Files in the LANSA for i User Guide.