`allegro`

 What's that?
`FAQ` 
Stated very briefly, allegro is an 
	`autonomous`, 
		`platform-independent`, 
			`object oriented` 
	`Database system`.
It can also (but not exclusively) be operated as a `Client/Server System`. 

This brief statement contains five concepts that should be explained in some more detail. 
(You can also click on the blue words.) 
Back to the `Overview`

A Database System (as opposed to a purpose-built library software suite)
This means that allegro is not a specialized application package but it can be configured for many different tasks that require the capturing, saving, managing, manipulation, retrieval, and evaluation of data. This kind of software has to have a number of features, among which are these: 

Parametrizability
Data structures cannot be "hard-wired" but have to be configurable and parametrizable. In particular, allegro is not confined to library-specific data and their idiosyncrasies, but it can cover a wide spectrum of structures and functions.

Multi-user capability 
An allegro database can be run on all platforms, incl. DOS and Novell, with simultaneous access from any number of workstations. There are no separate single-user and multi-user versions.

Resilience 
All transactions (data input, corrections, etc.) are logged in a separate file. In the event of a severe crash leaving the database in a corrupt state, it can be restored to the state immediately before the crash.

allegro is autonomous
No additional software, like a standard database platform, is needed to run allegro. This means: No extra cost or efforts. Simply stated: allegro does everything by itself.

allegro is platform-independent 
MS-DOS, UNIX, Linux, Solaris, Windows XP or '7 - A database can reside on any of these platforms. Not only this, but the file structure is exactly the same in all cases. Therefore, one need only copy a database to make it usable on one of the other patforms. If the same disk is accessible from two platforms, like DOS and Windows, both can access a database simultaneously. (The problem of different character sets is solved by a  tranparent table-driven mechanism.) Convenient client programs exist only for DOS and Windows (from '95 up). 
To publish a database on CD-ROM is as simple as copying it. Browser programs APAC (for DOS) and alcarta (for Windows'95 etc.) are free for distribution, i.e., buyers of the CD pay no license fees. 

allegro is object-oriented, not `relational`
An allegro database may hold records of various types. The behavior of a record, as for example its indexing or its appearance in the display, is governed by the parametrization, not by built-in functions. The Windows programs have a macro language called `FLEX`. This can equip records with all sorts of functions. 
The `Parametrization` concept makes allegro an open system: it is not a Black Box, but an industrious user can configure everything down to the minute details, including the conversion of data from outside sources into the local format or of allegro local data into other formats. 

Is allegro a Client/Server System? 
Yes and no. A database server named avanti is part of the package. This is normally employed only for WWW access. There's a long `Link list` of databases brought to the Web in this way. The avanti server also serves as an intermediary for  Z39.50 access. 
One may install the avanti server in an intranet but it is not necessary . Much more often, the  "monolithic" programs of the DOS  and Windows platforms are used in Novell or NT networks. They have a lot more functions and more power than a Client/Server system because they access the database directly and exploit the power of their workstation in a much better way. In particular, it would be quite clumsy to install a client/server system on a single user workstation. It is possible, but slower and a much bigger job to administer. Where necessary, avanti can, however, access a database simultaneously with the monolithic clients. This means, live databases can be accessed via the WWW . 
Besides avanti, there's a second method to make databases accessible by Web browsers in the internet or intranet. This rough-and-easy method is called "`RuckZuck`". It is explicitly meant for quick shots and available only on Windows-95/98 / NT. No time-consuming work in Perl or similar scripting languages is needed for this method, but it uses a ready-made package of  HTML files and some FLEX makros and parameter files. With this, a database can be online within an hour. Like everything else, this method is configurable and extensible. 

Is allegro fully documented? 
For the administrator, there is the `Systemhandbuch,` (in German). The Windows programs, a99 and alcarta, come with many help texts making orientation easy - they have hyperlinks like HTML files. You are just looking at one of these files. The big question-mark button at the lower left, between the [Index] and [Find] buttons brings up the documentation at any time, or type 'h' on the command line. There's not just text but also functions. Under the heading of `Supervisor Functions` you find all the necessary assistence for the management of databases, including backup copies and restoration. 

Is allegro something for small and medium databases? 
That would be an understatement. By now, there are many databases exceeding 1 million records, the biggest is beyond 7 millions and running on a Novell server. 

allegro is not a library system 
... as was stated above. Being freely parametrizable, allegro can be employed for library tasks but it was not developed with just that in mind. The package comes with a standard parametrization enabling a library to begin cataloging right away and establishing a local OPAC. There are more parameters for functions like circulation and book ordering. 

You want to know more about the system and its concept? There's another text telling the `background story`.

?Link list=~start http://www.allegro-c.de/ac-dbs.htm 
?autonomous=h >allegro is autonomous 
?platform-independent=h >allegro is platform-independent 
?object oriented=h >allegro is object-oriented 
?Database system=h =A database system 
?allegro=~start http://www.allegro-c.de 
?Client/Server System=h >Client/Server 
?Systemhandbuch,=h handbuch 
?Overview=h doku 
?background story=h backg 
?FAQ=h ac0-9 
?relational=~start http://www.allegro-c.de/a-r.htm 
?RuckZuck=h ruckzuck 
?FLEX=h flex 
?Parametrization=h ac10 
?Supervisor Functions=h super