The Yard Relational Database System
To use Yard, you must purchase a license for the SQL engine, plus licenses for one or more ancillary systems (ODBC, ESQL-C, YARD-X or JDBC).
Yard costs a fraction of what you would pay Oracle or Informix for a package with similar functionality. An SQL license for five users costs 990DM (not including value-added tax)—or about $490 US. (The actual cost will depend upon the rate of exchange between the Deutschmark and the US dollar, which fluctuates.) The other tools are similarly priced.
Unlike Oracle, which utilizes “named users” (that is, only a defined set of individuals can use the package), Yard defines a “user” as someone who is interacting with the engine. Thus, a five-user license can actually serve more than five users—a fact that is particularly important if your users work only intermittently with the database.
A free personal edition of Yard is available for download from Yard's web site (http://www.yard.de/). This package supports a single user and limits the size of the database. An ODBC driver is also available for the private edition. If you are interested in Yard, the private edition is an excellent way to become familiar with it.
Documentation comes in the form of HTML files. Some sub-systems also have PostScript versions available; in particular, these are available for the ESQL-C library.
Documentation is available in German and English. I do not speak German but I found the English documentation to be well-organized and complete and its English to be both correct and lucid. My only complaint is that the HTML version tends to put each sub-section into its own file, making it difficult to print a copy to read while you're away from your computer.
The documentation assumes that you know SQL and are thoroughly familiar with Linux. Again, Yard is not a package for beginners.
Installation of Yard is driven by a shell script and runs smoothly. The script requests a location for installing the binaries, requests license numbers and keys, then copies the bits appropriately. A complete installation of the engine, libraries, header files and configuration files takes less than 11 megabytes.
Installation, unfortunately, is hampered by minimal documentation. The only documentation you receive are two lines of instruction, printed on the CD-ROM case, telling you to mount the CD-ROM and invoke the installation script. Thereafter, you're on your own. If something goes wrong, your only recourse is to read the shell script and interpret what it was doing when it failed.
Thanks to this flaw, installation is practically guaranteed to fail at some point, at least on your first try. For example, nowhere does the Yard package indicate that the binaries must be owned by a user and group named yard—your first hint of this requirement is the obscure error message you see when the script fails.
This may be splitting hairs, but it is a pain to diagnose and fix problems that could easily have been avoided had the publisher included a page of instructions in a README file.
Yard is a fully implemented, enterprise-scale database-management package. With it, you can process transactions for a small- to medium-sized business or not-for-profit enterprise. It offers most of the features of Oracle or Informix, but at a fraction of the cost.
Since it is an enterprise-scale RDBMS, Yard may be too much database for some users. If you are looking for a tool with which you can learn SQL or if you wish to set up a small database for your church or fantasy-baseball league, you probably would be better off with a more modest commercial package, such as JustLogic, or with one of the free databases, such as PostgreSQL or msql.
However, if you are a contractor who specializes in Linux-based solutions or a business person who is considering using Linux as the backbone of your enterprise's information system, you will find that Yard is serious software worth serious consideration.
Fred Butzen is a technical writer and programmer who lives in Chicago. He is principal author of the manual for the Coherent Operating System, and is co-author of The Linux Database (MIS:Press, 1997) and The Linux Network (MIS:Press, 1998). He can be reached via e-mail at firstname.lastname@example.org.
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