WAIS - The Wide Area Information Server

WAIS is pronounced "ways", and was developed at Thinking Machines Corporation.

WAIS is a database system that exploits two recently popularised computer science concepts: the client-server model, and full-text databases.  It gives the ability for users to search existing databases of articles, books, references, abstracts and specialist information (such as genome databases, usenet group archives, ftp-site listings, etc), and for people with information to publish it at little expense and effort over the Internet.

The client-server model is a commonly used method of providing services over a network.  The end-user uses a client program to access information by communicating with a server program.  Typically the server and client are running on different machines and communicate over the network.  You need not have a server of your own to be able to use the client.

The full-text database is a model designed explicitly to search documents on any word that appears in those documents.  The old approach was to have a set of keywords which you could search on, and these words represented a small subset of all the words in the documents.

It is the WAIS client that lets you search databases.  Databases are provided over networks by WAIS servers.  Servers are available to run under System V and BSD releases of Unix, VMS, the IBM RS/6000, and the NeXT.  Client software is available for dumb terminal Unix, curses on Unix, GNU Emacs, Macintosh (with MacTCP), the NeXT, MS-DOS machines with and without Windows, as well as VMS, RS/6000, X Windows, OpenLook, Motif and Sunview. You can get these clients and servers from SunSITE.unc.edu via anonymous ftp. Look in the pub/wais directory. 

The fundamental concepts in WAIS are the database, the document, the source and the hit.  A source is a short text file that describes how a client can access a database that is provided by a server.  It typically lists the database name, the machine the server program is running on, a brief description of the database, the name of the maintainer of the database, and the cost (if any).

A document is the basic unit - when you perform a search and look at results, you will be looking at documents.  Databases hold lots of documents, and the server will search all the documents in the database.  When the server finishes the search, it sends the client a list of hits - the names of documents that looked like they matched what you were searching for.  A hit is one document name.

To try out WAIS, without compiling anything, you have to be on the Internet.  The following is a brief guide to the curses-based Unix client.  Telnet to SunSITE.unc.edu and log in as "swais" (do not type the quotation marks).  You will not need a password.  Then enter your terminal type when prompted for it (most will be vt100). You will then be connected to a simple terminal window client program, and will be presented with a list of names of databases to search (each name of a database corresponds to a source).

You can move through the list of sources with your arrow keys or the j and k keys.  The question mark (?) key gives you help.  To search for a word in the database names, use the / key.  For example, /sun will move you quickly to the databases relating to Sun computers. A database for selection will be highlighted. (For instance, SunSITE.unc.edu offers the "sun-fixes" database. Use the arrows or j keys to highlight that database name if you wish to search it). Once your cursor is on the source you wish to search press Return and you will be asked for keywords to search on.  (Notice that an * has been placed beside the selected source). Enter the keywords, separated by spaces (for instance, "mail sendmail", without quotation marks, would search for the words mail and sendmail). 

The client then gives you a list of hits - the names of documents that match your request.  You can move through the list with the same commands as before.  To view a document, press Return when the name of the document is highlighted.  Press H for help while viewing the document.  Press 'q' to leave from the list of documents.

Nat
(gnat@kauri.vuw.ac.nz -- Nathan Torkington -- is the electronic text and MS-DOS archivist for the Victoria University of Wellington, New Zealand)

Modified and extended for Sunsite by Paul_Jones@unc.edu