a codasyl cad data base system
If in CAD systems a CODASYL data base system is used, one has to avoid some well known disadvantages. To achieve this, we defined for CAD needs in application programs a special high level data manipulation language (HLDML). With this concept the application programs get independent from the data base structure and they are able to work with a many records at a time- view. Other provisions reduced some overhead caused by the used data base system.
data data base systems applications program manipulation language concept structure records timing