Client-Server vs. Flat File Databases

Multi-User Performance

In any "flat-file" database such as the Paradox data files TravisFlex for Windows uses, all application and data processing takes place on the individual "client" workstations. The file server of the network, where the data files are located, serves only as an unintelligent, shared hard disk. The server CPU remains largely unused.

When the database needs to be updated, all necessary table and index data is read from the server, across the network, to the client workstation. Actual updates occur on the client workstation. The new data is then sent back across the network where it is written to the file server. When a piece of information needs to be found in the database, a search of the database is required. Index data must be read from the server, across the network, to the client workstation where the search of the data takes place.

Index data must be continually read over to the client workstation until the desired data is found or until it is determined that the data does not exist in the database. As more users are added to the system, the larger the database becomes, the amount of data transferred across the network increases even more, and performance deteriorates.

Client-server systems move the processing to the server, reducing network data traffic. Data updates occur on the server, not the workstation, and index data does not travel across the network, eliminating errors in the data files. A high number of users in the system at any one time in a client-server environment does not compromise the systems, as the client-server database regulates the storing and retrieval of all the data.

Database Stability

During interaction between a "flat file" database server and a workstation, tables and index files are susceptible to corruption. Workstations can be interrupted or fail because of a reboot, power failure or memory problem. It takes several tries (calls) between the workstation and the server to complete a data update operation - if during this process the application, workstation or network fails, the operation is partially executed, leaving the database in an unknown state. Index file stability and possibly table stability are compromised, resulting in data corruption and the Travis user having to send their data to Travis to be repaired.

In the client-server version of the system, the data files are centrally updated and managed, resulting in faster and more secure data updates. The database on the server is independent of the workstation, so if it, the application or the network fails, the data is not compromised and no corruption occurs.

There are other, more technical, advantages of client-server databases, in the area of Database Security Options and Transaction Processing. But for most Travis customers with either a high number of users in the system, a large database, or both, the ability to eliminate data corruption and index errors, and to support an increasing number of users, may be enough to seriously consider upgrading to the client-server version of TravisFlex.

Contact Info:
Travis Software
Garth Williams
Vice President
(281) 496-3737