|
Paradox is a relational database management system currently published by Corel Corporation. It was originally released for DOS by Ansa Software, and then by Borland after it bought the company. A Windows version was released by Borland in 1992. ==Paradox for DOS== Paradox for DOS was a relational database management system originally written by Richard Schwartz and Robert Shostak (brother of Seth Shostak), and released by their company Ansa Software in 1985. In September 1987, Borland purchased Ansa Software, including their Paradox/DOS 2.0 software. Notable classic versions were 3.5 and 4.5. Versions up to 3.5 were evolutions from 1.0. Version 4.0 and 4.5 were retooled in the Borland C++ windowing toolkit and used a different extended memory access scheme. Paradox/DOS was a successful DOS-based database of the late eighties and early nineties. At that time, dBase and its xBase clones (Foxpro, Clipper) dominated the market. Other notable competitors were Clarion, DataEase, R:Base, and DataFlex. The features that distinguished Paradox/DOS were: *A visual Query by Example implementation that was supported by an AI engine. *Effective use of memory (conventional as well as extended / expanded) - caching data tables, and particularly indexes, which caused Paradox to execute tasks very quickly in contrast to the explicit skills required for xBase performance optimisation.〔Unfortunately the memory management is based on the early VCPI standard, and Paradox 3.5 and earlier will not run in modern DOS emulators, nor in pseudo-DOS environments like Windows 95. Paradox DOS 4.0 and 4.5 run fine under all versions of Windows except Windows 2000, which causes a choice of two uncorrectable abort failures.〕 *An innovative programming language the Paradox Application Language (PAL) that was readable, powerful, and could be recorded from keyboard actions (rather like Lotus 1-2-3 macro recording). *Lotus-like text menus and windows which was the native interface (in contrast to dBase which had a command line interface with menus layered on top). *Particularly in Paradox 1.0 and 2.0, the user and programming manuals won readability awards - they were copiously illustrated, well laid out and explanations were written in common English. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Paradox (database)」の詳細全文を読む スポンサード リンク
|