DP4 is a development environment for creating database applications to run on PC workstations. DP4 is used for developing systems of all levels of complexity for business areas such as retail and banking. The core system consists of an ADE (application development environment), and a runtime environment.
The DP4 application development environment provides you with the tools for designing and implementing a database application based on the relational model. A relational database stores information in tables, and allows record selection using the keys in the table. The DP4 relational database allows you to look at and edit more than one table at a time. For example, if you have a set of customer records and a set of order records, you can look at and change both sets of information simultaneously.
DP4 supports the development of your database from entity modelling and table specification through to database distribution and maintenance. The development environment provides a complete set of tools for the creation of application programs in C/C++ (other lanaguages are supported on some platforms), and fourth-generation environments such as QA Build and Report Writer.
The DP4 runtime environment supports a client/server architecture, with the possibility to use the server machine as an additional workstation. You can configure DP4 to suit the requirements of your system. The configurations range from a simple networked system, with one server and several clients, to more complex systems that use more than one server for distributed databases. You can set up your system to ensure non-stop working of an application using the DP4 resilience scheme.
If you wish to use special-purpose devices such as scanners, receipt printers and LED displays, you can access these from within your DP4 application programs. You can view and update data stored in databases and file systems from other suppliers, and they can update DP4 databases.
The DP4 runtime environment is supplied for Microsoft Windows from Windows 3.1 right up to Windows 2000 and Windows Me, many Unix and Linux platforms including high end platforms such as the Sun Solaris and IBM RS6000, as well as legacy platforms such as MS-DOS,FlexOS OS/2 and Presentation Manager. The supported network environments are TCP/IP,IPX/SPX, NetBIOS, TCP/IP and FlexNET.
The application development environment uses all the features of the runtime environment. As a result, you can develop and test an application on one operating system, and port to another platform with little or no extra development time. You can develop an application independently from the devices and the network configuration that will be used for the delivered system.