Curriculum Vitae of db++

Using the db++ modules dbcreate and dbappend, relations can be specified and filled with imported data in double quick time without the need for exhausting definition aria. The swift application of dbmodify during or after this process will structure the relations for efficient indexed access over diverse types of primary and secondary indices.

Here a titbit, each relation is a single file containing both data, indices and structural information - usually in Btree form - with powerful algorithms developed by Concept asa for an extremely efficient and automatic rollback using the bitmap controlled shadow storage concept. For the application programmer this means that many standard Unix commands can be applied to db++ relation files and combined with specialised db++ commands, for example in pipe lines.

The integration of db++ utilities in the Unix environment should not be underestimated: it saves considerable administration effort and dramatically reduces the learning curve involved with gaining familiarity with a large number of specialised propriety database tools.

This characteristic that "db++ runs not under but with Unix/Linux" is means that customising of application programs - e.g. turn-key solutions for wholesale/retail and material requirements planning - to realise specialised client requirements can be undertaken by personell with limited knowledge of db++.

It is nice for the professional developer to know that his application will just run and run - like the one time famed Volkswagen Beatle - without needing to employ specially trained database administrators at the client site. But for the programmer of custom software, the effiency of the development cycle is paramount.

And just in this area, those developers who have fallen in love - and who can blaim them - with the the ubiquitous "mega tools" perl from Larry Wall and Tcl/Tk from Professor John K. Ousterhout will be delighted.

db++ has direct interfaces to perl, Tcl/Tk and Java as well as the traditional "C" programming interface. The cdbServer is now also programmable in Tcl at run-time. This means that functionality which would previously have been programmed on the client side can now run within the cdbServer (actually we should speak of the cdbServers since one or more cdbServers can be running on any host in the network). This can cut network traffic by an order of magnitude and thus considerably improve the already very high performance of db++ transactions.

Both the perl and Tcl/Tk interfaces permit the programmer to model and develop highly specialised database access methods in an extremely simple and efficient fashion. Especially the possibility of externalising client specific functionality in perl or Tcl scripts frees C and/or C++ code from client specific code. Maintaining and modifying such tailor made code - even for the most esoteric of client desires - is reduced to a minimum.

Even if you do not share our opinion that Tcl is the only serious contender for the accolade "the (non-proprietary) 4GL language for the 90's and beyond" and are not impressed by the huge world-wide community of users (and testers) which are in constant dialogue with each other and John K. Ousterhout via the Internet, db++ also provides interfaces to ODBC and to Java.

At present the Java interface has been mainly installed for browser based retrieval front ends to implement an efficient connection from an applet to a remote db++ search engine.

Aficionados of db++ have often been heard to ask:

Is db++ flexible and simple - or just simply flexible?

• Example Data storage: In contrast to other database management systems, all string fields in db++ have been of variable length - so strings turn out to be longer than anticipated at the database design stage; no problem - and no need to make changes to a data-dictionary or rebuild relations. All db++ needs to know about the relation structure is stored in the one relation file together with the data and index trees. And there is no wasted space - each and every string uses just that space which it needs. Copy the relation to another system, then don't worry that you forgot to copy structural information - it's already there. Application programmes have no problem in working with different relation structures, i.e. the article relation for a jellied eal business will have a different structure from that of a car component wholesaler but the same programme eats both relations. Problems with sorting? Not with db++ - Strings can be sorted by ASCII or collated by national idiosyncracies, i.e. German Umlauts - Ä after A, Ö after O and so on.
• Example Query:Where other database systems offer dialogue oriented methods, db++ "only" has a query processor without a user interface. The processor is fed with commands in the "relational algebra". But: Developers and users are not condemned to learn yet another user interface. Rather the db++ query process remains discretely in the background from where it executes AQL commands sent to it by the application, processing large volumes of data quickly and securely. Just what a query processor is designed to do.
• Example Report generator: If you know perl then you already know one of the available report writers for db++. The fusion of the genial script language perl from Larry Wall with db++ presents the developer with unimaginable possibilities to realise anything from simple to very complex reports. Even complete applications can be realised in dbperl. For less complex problems, the alternative report writer "dbrpg" with a syntax similar to awk is also available.
• Example ODBC: Users at home in the Microsoft world but without experience of either Unix or even database languages can use the ODBC interface. The db++ ODBC driver permits a seamless connection of MS-Office or other ODBC-related tools to your database using the ODBC/SQL protocol over TCP/IP.
• Example Tcl and Java: Why both Tcl and Java? In contrast to pre-compiled Java applets, data and programme are interchangeable in Tcl and can thus be modified at run time. By combining the advantages of Java on the client side - zero installation and maintenance costs - with the powerful string and list handling, pattern matching with the dynamic programmability of Tcl at the server, the application programmer has the highest degree of flexibility handed to him on a plate. Thus a Java applet can send a Tcl request to the dbServer and the server might answer with a formatted text element. The resulting ease with which database functions can be dynamically formulated and combined with pure string operations extends the conventional "stored procedure" concepts of other database systems by an order of magnitude.
• And last but not least: db++ is slim, trim and terrific. All the db++ tools have been programmed in the good old Unix tradition - one tool to do one job well. Database queries can be stored in or generated by shell scripts and the results formated with troff and friends. Pipe data to and results from one db++ tool or standard Unix command to another. The limits exit only in your own imagination.

Ask Concept asa about typical applications built with the db++ database system - the answer is in the first line commercial applications. Thus there are, for instance, ca. 800 installations of wholesale turn-key systems and considerably more than 10.000 installations of a payroll package developed with db++.

In total there are somewhat more than 15.000 installations (sites), running on Unixware of Novell, Sun Solaris, HP-UX, IBM AIX, Sinix, Linux and Windows platforms. Whereby the last two platforms are now dominant.

Scalability: Typically a site will support between 2 and 100 work-stations (terminals and/or PC's) accessing one or two server machines but installations with up to 300 work stations, sometimes up to 500 simultaneous client processes accessing up to 5 GB of user data can be handled easily with a single dual processor Pentium4 machine with 1024 MB RAM on both LINUX/UNIX and MS-Windows platforms. By request from EADS Airbus the upper 2 GB limit to the size of a single relation/table has been removed for the Sun Solaris version.

Since db++ still fits on to a single diskette, we expect that in the near future a new application area will arise in the embedded Linux market where db++ would require no more than 2-4 MB Flash and 4-8 MB DRAM.

In addition to commercial applications, db++ has a smaller but significant installed base in the public sector: For instance, at 120 different sites in North Rhine Westphalia; A number of technical applications in the area of network control, administration and statistic especially by the German Telekom and in the banking sector; Several interesting applications in the area of process and quality control; Several installations in the area of technical documentation.

Curriculum Vitae of db++

Concept asa GmbH

Obere Pforte 1

D-35428 Langgöns

Tel: ++49 (0)700 777977-71, Fax: -99