Dataphor
From Wikipedia, the free encyclopedia
Dataphor is an opensource truly relational database management system (TRDBMS) and its accompanying user interface technologies, which together are designed to provide highly declarative software application development. The Dataphor Server is a virtual, or federated, DBMS, meaning that it utilizes other database engines for storage.
Contents |
[edit] Overview
The stated purpose of Dataphor is to attempt to raise the bar of automation when building and maintaining complex software applications. Originally referred to as a framework, Dataphor provides more of a software development platform, complete with its own programming and user interface paradigms.
Dataphor is broadly comprised of two components: the Dataphor Server, and the Dataphor Frontend. The purpose of the Dataphor Server is to provide a standardized language and runtime for the definition, manipulation, and integrity of application data. The Frontend is concerned with the dynamic derivation of user interfaces and the presentation thereof in either the Windows or Web thin client.
Dataphor does not employ SQL as its primary database language since SQL purportedly violates important principles of the relational model. Dataphor's D4 language is based on the principles of Christopher J Date's and Hugh Darwen's Tutorial D, but with a Pascal-like imperative syntax.
Though Dataphor espouses to be truly relational, it does incorporate the concept of NULLs as found in SQL, which many claim to be contraindicated by the Relational Model. NULLs and the matter of managing missing information, however, continue to be debated.
In addition to the data management focus of the Dataphor Server, Dataphor includes tools which allow the presentation of user interfaces through Windows and Web "thin" clients. Dataphor takes advantage of the relational inference capabilities of the Dataphor compiler in order to allow complete GUI forms to be derived directly from the data model. The unique aspect of Dataphor's user interface "derivation" is that it may be based on any relational expression (query) rather than merely base tables.
[edit] History
Dataphor was originally created as a commercial product by Alphora, a division of Point of sale systems developer Softwise Inc. It is said to be the first truly relational DBMS since IBM Business System 12. Development of Dataphor began shortly before 2000, with a 1.0 release in 2001.
In early 2008, the Alphora name and the Dataphor product were acquired by Database Consulting Group, which was founded by the original architects of Dataphor, who left Softwise in 2007. After the acquisition, Dataphor was re-licensed as open source under the BSD license.
[edit] Technology
Dataphor utilizes the Microsoft .NET Framework and is written entirely in C#. The following is a summary of the various technology components of Dataphor:
[edit] Dataphor Server
The Dataphor Server has several components including:
- Call level interface - session management, process scheduler, etc.
- Data Dictionary Catalog - containing all of the Tables, Views, Operators, Constraints, References, and other schema objects.
- D4 Scanner, Parser, Emitter, and Compiler.
- D4 Runtime - including relational, and scalar processing
- Storage Integration layer - real-time translation to various dialects of SQL
[edit] Frontend Library
The Dataphor Frontend library provides for the delivery of dynamically derived, or pre-designed static forms. The library is exposed as a standard set of D4 functions (called operators in D4) such as Form('<library>', '<name>') and Derive('<D4 expession>', '<form type>'). The resulting forms are described in an XML dialect called a Dataphor Form Document (DFD). The form description is high-level, consisting of a general description of the user interface aspects as they apply independent of client platform.
[edit] Dataphoria IDE
Dataphoria is a development environment for:
- Editing D4
- Ad-hoc execution of D4
- Creating, Editing, and Customizing (inherited) forms
- Managing libraries
- Analyzing execution plans
[edit] Windows Client
The Dataphor Windows Client is a thin client in the sense that it is not pre-programmed for a particular application. The Windows client establishes a connection to a Dataphor Server, from which it (through D4) requests form definitions and coordinates the manipulation of application data. The DFD documents are interpreted into concrete Windows Forms controls, but while maintaining the conceptual DOM of the DFD.
[edit] Web Client
The Dataphor Web Client is a basic implementation of a Dataphor client, which is manifest as an ASP.NET web application. Like the Windows Client, the Web Client connects to and requests forms and data from and instance of the Dataphor Server. Rather than synchronizing a DFD to Windows controls, however, the Web Client renders HTML which is displayed in a browser. In this way, the Web "Client" is a client relative to the Dataphor Server, but a server relative to the end web browser.
