What Is D3?

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Category	Preface
Type	Introduction
Description	A general description of D3. D3 is an on-line computing environment that allows many users to share a computer and a data base. It is a generalized data base management language and system that provides tools to manage information in a flexible, efficient, and timely manner. The essence of developing an application with D3 is to define the problem in terms of information and relationships between information. D3 has been used to develop thousands of application packages used by more than two million people since the late 1960’s. Some of the reasons or Pick's success are - Applications can be developed faster and easier with D3 than with traditional systems. - Applications written in D3 run faster than those written in traditional languages. - D3 uses fewer resources - cpu, disk, and memory - due to its unique data structure and processing techniques. Pick makes micros perform like mainframes. - D3 makes users more productive. Users conserve time and resources and can operate applications more effectively and efficiently. - The multibillion dollar D3 marketplace is growing nearly 50 percent per year with more than 4,000 commercial applications available. - D3 is available on more computers than any other single environment. Usage of the D3 standard guarantees lifetime hardware freedom. Applications written in D3 today will run on the computers of the future. D3 is a multi-user system. It supports many terminals and runs many jobs simultaneously. Processing originates with commands entered at the keyboard using Terminal Control Language (TCL) and Access statements, which are a combination of verbs and parameters contained in files called master dictionaries (MDs). Each set of interrelated files (a data base) in D3 is organized around a master dictionary. The master dictionary contains the verbs (both provided with the system and cataloged programs that are part of an application), macros, menus, connectives, and file names needed to process the information in its data base. The system can be customized to fit the needs of each user. The master dictionaries to which a user has access and the items in those master dictionaries determine the features available to that user. For example, the master dictionary for personnel might include all employee information and can be accessed by one set of users, while the procedures master dictionary might contain procedures on company policy and can be accessed by a different set of users. Furthermore, access to features within a master dictionary may be limited through various security features, such as user privilege levels and update and retrieval lock codes. What is D3? D3 retains all the functionality of earlier R83, Open Architecture (OA) and Advanced Pick (AP) releases, while adding tools supporting dramatic improvements in the way applications are developed. In D3, an application is created with minimal source code. This is achieved by utilizing the inherent file structures and many application generation tools provided by the operating system. These tools include the Update and Output processors, processing codes, extended Access, and FlashBASIC capabilities, as well as macro and menu utilities. Level pushing provides the ability to interrupt a process and invoke any of these other tools on a new level. The interrupted process is pushed onto a stack and can be resumed at the exact location it was interrupted. Up to 16 levels can be pushed. This enhanced system mobility is a boon to development activities. The improved B-tree structure allows for indexing and enhanced file searching capabilities. Processing codes, residing in three specific attributes of a dictionary item (the input conversion, correlative, and output conversion attributes), provide the ability to maintain and update files without the need of a FlashBASIC program. These processing codes are used by D3 processors to define operations on data within the associated files at the system rather than program level. The processing codes include: - Algebraic functions, - Assembly code executions, - FlashBASIC subroutine calls, - Edit patterns, - Input and output formats, - Data conversions, - If..then..else constructs. The primary user interface to D3 is the Update processor. The Update processor is a dictionary-driven, full-screen editor and data processor. Refer to the "Update Processor" Introductory topic at the front of this book and the entry "Update Processor" in the body of the Reference Manual for more information. Installing D3 Pick Systems has provided a state-of-the-art multidimensional database management system which is portable to many different hardware configurations, giving the user the most up-to-date system-level capabilities, plus the ability to upgrade hardware without the fear of needing to redevelop software. Refer to the installation guide that came with your D3 package for detailed installation instructions.
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Compatibility	D3 7.0 R83 AP

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