|
The logical layer is held to be the Relational Model. Here we have the "Relational Data Model" using "Relational algebra", where Codd's "Relational calculus" operates. This is where the Relational Database Management System (RDBMS) exists. In the ideal system (which, of course, does not exist), the storage layer can be adjusted and tuned for performance while the logical [custom essay] layer and its constraint logic is unchanged. |
|
The logical layer is held to be the Relational Model. Here we have the "Relational Data Model" using "Relational algebra", where Codd's "Relational calculus" operates. This is where the Relational Database Management System (RDBMS) exists. In the ideal system (which, of course, does not exist), the storage layer can be adjusted and tuned for performance while the logical layer and its constraint logic is unchanged. |
|
In the Multi-Value model there is no DBMS as such. The [essay paper] definition used for data presentation does not provide constraint checking on data updates. All controls are enforced by the application. However, there have been a large number of application generators and fourth generation languages developed in MV. I remember writing one myself that took my specification and generated working code. It took me two weeks to write and produced 50,000 lines of code in 20 minutes for something over 100 programs (data entry, menus, and reports). I think the reason why I (and so many others) could do this was that the particular type of BASIC used in MV is really good at handling strings, including strings of source code. |
|
In the Multi-Value model there is no DBMS as such. The definition used for data presentation does not provide constraint checking on data updates. All controls are enforced by the application. However, there have been a large number of application generators and fourth generation languages developed in MV. I remember writing one myself that took my specification and generated working code. It took me two weeks to write and produced 50,000 lines of code in 20 minutes for something over 100 programs (data entry, menus, and reports). I think the reason why I (and so many others) could do this was that the particular type of BASIC used in MV is really good at handling strings, including strings of source code. |
![[Home]](/pickwiki_logo.gif){kind=logo}