DBASE
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- The title of this article is incorrect because of technical limitations. The correct title is dBASE.
dBASE was the first widely used database management system or DBMS for microcomputers, published by Ashton-Tate for CP/M, and later on the Apple II, Apple Macintosh and IBM PC under DOS where it became one of the best-selling software titles for a number of years. dBASE was never able to transition successfully to Microsoft Windows and was eventually displaced by newer products like Paradox, Clipper, and FoxPro. dBASE was sold to Borland in 1991, which sold the rights to the product line in 1999 to the newly-formed dBASE Inc.
Starting in the mid 1980's many other companies produced their own dialects or variations on the product and language. These included FoxPro (now Visual FoxPro), Quick-Silver, Clipper, Xbase++, FlagShip, and Harbour. Together these are informally referred to as xBase or XBase.
dBASE's underlying file format, the dbf file, is widely used in many other applications needing a simple format to store structured data.
dBASE was licensed to users for a term of fifty years in the unlikely event that a user would use their copy of dBASE for a long period of time.
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History
dBASE's history can be traced back to the mid-1960s in the form of a system called RETRIEVE, which was marketed by Tymshare Corporation. One of RETRIEVE's users was the Jet Propulsion Laboratory, and in the late 1960s they asked one of their programmers, Jeb Long, to produce their own customized version. The result was JPLDIS (Jet Propulsion Laboratory Display Information System) which was written in the FORTRAN programming language and ran on their UNIVAC 1108 mainframes.
In 1978, C. Wayne Ratliff, another programmer at JPL and friend of Jeb Long, wrote a database program in assembly language for the CP/M operating system based on JPLDIS. He called it Vulcan, after Mr. Spock of Star Trek. According to an article written in 1982 by Stan Brin for Popular Computing, Vulcan was written to help him win the football pool at the office. After more work, and successfully using it to do his taxes, he felt it might have some commercial potential.
In October 1979, and for four or five months thereafter, the first quarter-page ad for Vulcan appeared in BYTE magazine, selling for US$7000 per copy. The commercial response was poor. By the summer of 1980 the stress of working his day job while enhancing the product was too much, and he decided to stop marketing it altogether, and only support those who had purchased it up to that time.
Ashton-Tate
A professor at the University of Washington and his wife were considering taking over marketing when George Tate and Hal Lashlee received a call from a Vulcan customer and went to see Ratliff and a demo of Vulcan. George and Hal already had a business called Discount Software, with one employee. They made an offer for exclusive marketing rights, and Wayne accepted. This arrangement continued for about two or three years. By '82 the company had hired Ratliff as the vice president of new technology. By 1983 the company was so successful that they did an IPO.
Ratliff was later the project manager for dBASE III, as well as designer and lead programmer. Jeb Long was also hired about this time, and worked there for 8 years. He was known as the guru of the dBASE products at Ashton-Tate, and was the architect of dBASE' internal programming language.
dBASE III
The original versions of dBASE were all coded directly in assembly language, but as the program grew the decision was made to re-write the next version, a major upgrade, in the C programming language. This proved to be fateful; while dBASE-III, released in June 1984, ran acceptably on newer machines, it was too slow on older PC's and most customers ignored it. Additional releases of the II product continued while they worked on the performance problems, eventually addressing most of them by late 1985.
Mac products
Around 1986 Ashton-Tate caught "Mac fever" and started developing a full suite of Macintosh applications. They purchased a small company called Ann Arbor Softworks who were busy working on "high-end" business applications, and eventually released their spreadsheet called Full Impact, a word processor called FullWrite Professional, and, of course, a database called dBASE Mac.
FullWrite and FullImpact followed earlier patterns and were released filled with bugs, running slow on common hardware, as well as being over two years late. The products never sold well, with good reason, and Ashton-Tate soon gave up on the whole project, adbandoning FullWrite just as it appeared to be maturing into a powerful system. FullWrite was later resurrected in 1994 by an enterprising 3rd party, but by that time Microsoft Word had taken over the entire market.
dBASE Mac was utterly unlike their PC products, including a full GUI that made some complex tasks much easier, as well as offering a full GUI editor for data input. The program was generally lauded as the right way to do a database, but with no ability to share data with their PC versions it had to compete with other Mac-only databases such as 4th Dimension, Helix and FileMaker which were even better. After throwing in the towel they decided to release a direct port of then-current dBASE-III complete with a DOS interface.
dBASE IV
dBASE-IV was released in October 1988 and was incredibly buggy. Sales started to slump, notably due to the presence of dBASE clones such as FoxBase and Clipper. Ashton-Tate decided the proper response to FoxBase was to sue them. In the discovery phase it was learned that the intellectual property rights belonged to JPL, not Ashton-Tate, and the suit ended that quickly.
The company was soon insolvent, and was purchased by Borland in 1991. The problems with dBASE-IV were eventually fixed, and it was also ported to a number of "high end" platforms such as the Sun SPARC, IBM's AIX and DEC's VMS. dBASE-IV remained their primary product until early 1993.
dBASE 5
dBASE 5.0 returned to their roots with a pure-PC version available both on DOS and Windows. By this point, 1993, dBASE's market share was plumetting. Borland eventually decided sales were small enough to stop production, but instead sold the rights to dBASE Inc., a small company dedicated to keeping the product alive. Although dBASE Inc. continues to release new versions of the dBASE platform — including an object oriented update for Windows platforms called dBASE Plus — dBASE is no longer a force in the database software market, and does not compete with products subscribing to the SQL standard.
dBASE programming language
dBASE has a proprietary programming language built into it for making queries and manipulating data. Many feel it makes a good ad-hoc data conversion and analysis tool because unlike SQL, one can easily view and save intermediate steps.
Critics of the language point to its "modal" nature, meaning that how a given statement acts depends heavily on its environment's settings. However, used in an event-driven environment, modal scope is less of a problem. Its modal nature also keeps it compact in many cases because one does not have to keep supplying context, handles, or paths to each and every statement in a related group.
Programming example
The following example opens an employee table ("empl"), sets a "filter" to view only managers (those who supervise one or more employees), gives every manager a 10-percent raise, displays the result in a tabular grid, turns off the filter (to show all employees, not just managers), and then prints the names and salaries of all employees to a printer. (Filters trump the "all" scope.)
use empl set filter to supervises > 0 replace all salary with salary * 1.1 browse set filter to list all fname, lname, salary to print
dBase was also one of the first business-oriented languages to implement string evaluation (long before Perl)
i = 2 myMacro = "i + 10" i = &myMacro // i now has the value 12
Here the "&" tells the interpreter to evaluate the string stored in "myMacro" just like it was programming code.
Niches
Although the language has fallen out of favor as a primary business language, some find it an excellent interactive ad-hoc data transformation tool. Unlike SQL, one can easily break data transformations into small steps to analyze and visually inspect. It allegedly fills the gap between formal RDBMS and array-oriented languages such as APL's modern derivatives (usually with single-letter names such as J, K, L, etc.)
.dbf file format
A major legacy of dBASE is its .dbf file format, which has been adopted in a number of other applications. For example, the shapefile format developed by ESRI for spatial data in a geographic information system uses .dbf files to store feature attribute data. The term XBase is often used for the group of applications.
dBASE's database system was one of the first to provide a "header" section for describing the structure of the data in the file. This meant that the program no longer required advance knowledge of the data structure, but rather could ask the data file how it was structured.
External links
- dBASE, Inc. (http://www.dbase.com/)
- An interview with C. Wayne Ratliff describing his career and history of Vulcan/dBASE (http://www.foxprohistory.org/interview_wayne_ratliff.htm)
- Xbase ( & dBASE ) File Format Description (http://www.clicketyclick.dk/databases/xbase/format/index.html)
- Adam Green - lectured on dBase for 12 years in the eighties (http://adamgreen.org/)
- C2 Wiki Description of "XBase" (http://www.c2.com/cgi/wiki?ExBase)da:DBASE