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Paradox (database) - Wikipedia, the free encyclopedia

Paradox (database)

From Wikipedia, the free encyclopedia

Paradox is a relational database management system currently published by Corel Corporation. It was originally designed for DOS but a Windows version was released by Borland in 1992.

Contents

[edit] Paradox for DOS

Paradox for DOS was a relational database management system originally released by Ansa-Software. 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, dbFast, Clipper programming language, dbXL) had the lion's share of the market. Other notable competitors were Clarion, Alpha Four (pre-dated Alpha Five), DataEase, R:Base, Dataflex, MDBS Knowledgeman.

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.
  • 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 on top of which cumbersome menus were layered).
  • 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. In contrast, xBase and other manuals were text heavy, sometimes even typed in plain Courier with no attempt at professional page layout.

[edit] Paradox for Windows

Paradox for Windows was a distinctly different product produced by a different team of programmers. Although key features of the DOS product, the QBE and the database engine, were ports keeping the DOS code, there was a major break in compatibility from PAL to ObjectPAL and in the shift to a GUI design metaphor for Forms and Reports. The ObjectPAL changes were controversial but forced since PAL was based on keystroke recording actions that had no equivalent in Windows. An object-based language based on ideas from Hypercard was used in place of keystroke recording. The Forms and Reports designers used device independent scaling including ability to work in zoomed mode for detailed layout. The mouse right-click was used for access to Forms and Reports properties, inspired by the Xerox Alto and Smalltalk, in a way now almost universal to Windows programs. The ObjectPAL was (like Hypercard) associated with the visual objects - also revealed by right click. Property inspection and layout tools could be "pinned up" to stay on screen, an idea borrowed from the NeXT and now fairly widely adopted in Windows.

For approximately the first year of development the object-oriented code was written in C aided by macros, until Turbo C++ was available at which point the remaining parts of the code were written in C++. The product manager up until shipping version 1.0 was Joe Duncan. The development and QA team totaled about 30 people.

Both Paradox for Windows and Quattro Pro for Windows, a closely related project, started development using beta versions of Windows 3.0, in the spring of 1990. Paradox/Windows ended up delayed about a year beyond its original plan, shipping in early 1993. The reasons were many, but not entirely surprising for a major rewrite, in OO language with new tools, shifting to a GUI paradigm, on what was essentially a first version operating system. Still it was a big problem for the company and Microsoft managed to ship Access a couple of months ahead of Paradox for Windows, a major marketing win to Microsoft.

In 1990 Borland also started work on an internal dBASE clone for both DOS and Windows, written in assembler, which was planned to ship in 1992. By early 1992 it became clear that Ashton-Tate was in difficulties on developing Windows versions of their products and so Borland switched plans, instead acquiring the company and anointing their internal project as the official successor. Part of the Ashton-Tate acquisition was the Interbase database and it was decided that Paradox/W should be able to work with Interbase as well as the Paradox engine and this lead to the creation of an IDAPI engine based around Interbase.

The acquisition also shifted focus. Paradox had historically competed against dBASE in some markets, and Paradox/W originally was designed to improve the competitive position in the developer-oriented market. After dBASE was acquired this was no longer desirable and emphasis shifted towards an ease-of-use market. However the product could not be changed to match the emphasis (this occurred in later releases) at that late stage, making the product somewhat over complex for the entry level market. Access did a good job of addressing that same market and got there first, by Christmas 1992. Still, Paradox/W sold well for a while. Meanwhile, Borland was going through some serious problems caused by the Ashton-Tate acquisition. Many product lines were discontinued, corporate reorganization and consolidation was painful, and even worse the internal dBASE project at the center of the acquisition rationale was eventually cancelled for technical reasons leaving Borland with a collapse in revenues and a serious need to develop the missing dBASE for Windows in a hurry. Borland had lost the strength to fight the multiple marketing battles it needed for its range of products. Paradox was minimally marketed to the developers since the company decided it would hold out for a replacement of dBASE, which eventually came out in 1994, too late for the company.

Microsoft Access was sold for a fraction of the price of Paradox/Windows and bundled with Word, Excel and PowerPoint in Microsoft Office Professional. Furthermore, Access performance was good thanks to team contributions from FoxPro programmers. Despite solid follow-on versions with improvements to usability for entry-level users, Paradox faded from the market. It was included in the sale of Borland products to Word Perfect, which were in turn resold as Word Perfect got into financial products, and at the current time of writing Paradox for Windows, Word Perfect and Quattro Pro for Windows are all owned by Corel and sold as part of their office suite. dBASE for Windows came out too late to be a significant player in the Windows market, most dBASE programmers by then had migrated to Microsoft FoxBase, a very similar database tool. Borland itself retained the Interbase/IDAPI server and focussed efforts on its Delphi tools which over the years gave it an influential but small part of the data-oriented developer market.

[edit] Corel Paradox

Corel acquired certain rights to develop and market Paradox in the mid-90's and released Corel Paradox 8 in 1997. It also bundled Paradox in the professional version of its WordPerfect Office suite. It has released versions 9, 10, 11, 12 and the latest version Office X3 Professional Edition since then.

[edit] Paradox Users

There is a strong Paradox user base, mainly centered around the Paradox Community and its associated newsgroups. Many feel let down by Borland and Corel because they believe that Paradox is superior to all the other desktop DBMS's around. Although there are many fans of ObjectPAL, the programming language for Paradox/Windows, PAL/DOS scripts could not easily be migrated; the object and event models were completely different forcing developers using PAL to completely rewrite their database applications.

[edit] See also

[edit] External links


Topics in database management systems (DBMS)view  talk  edit )

Concepts
Database • Database model • Relational database • Relational model • Relational algebra • Primary key, Foreign key, Surrogate key, Superkey, Candidate key • Database normalization • Referential integrity • Relational DBMS • Distributed DBMS • ACID

Objects
Trigger • View • Table • Cursor • Log • Transaction • Index • Stored procedure • Partition

Topics in SQL
Select • Insert • Update • Merge • Delete • Join • Union • Create • Drop

Implementations of database management systems

Types of implementations
Relational • Flat file • Deductive • Dimensional • Hierarchical • Object oriented • Temporal • XML data stores

Components
Query language • Query optimizer • Query plan • ODBC • JDBC

Database products

Apache Derby • Berkeley DB • Caché • DB2 • db4o • DBase • eXtremeDB • Filemaker Pro • Firebird • Greenplum • H2 • Helix • Informix • Ingres • InterBase • Linter • Microsoft Access • Microsoft SQL Server • Mimer SQL • MonetDB • MySQL • OpenLink Virtuoso • Oracle • Oracle Rdb • Paradox • Perst • PostgreSQL • SQLite • Sybase IQ • Sybase • Teradata • UniVerse • Visual FoxPro


Other: Object-oriented (comparison) • relational (comparison)

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