Enterprise level databases are a completely different animal to their desktop and workgroup level cousins - they are very much more powerful, sophisticated, robust and expensive. The larger databases like Oracle and IBM's DB2 are so complex that they invariably need specialist staff called DBAs (Database Administrators) to maintain them. 

On the positive side you would never expect to see any data corruption, there is no practical limit to the amount of data that can be stored and the speed is an order of magnitude greater than desktop and workgroup databases. There are a wealth of technical differences giving vast improvements in areas like security, multiple users (no record locking for example) and resilience. 

If a server running an enterprise level database loses power during a record being saved no data is corrupted.  If this happens with a desktop product data is likely to be corrupted not least because the indexes are likely to be out of alignment.

The main enterprise level databases in descending order of power and complexity are probably Oracle, IBM's DB2, Sybase, Microsoft SQL Server and MySQL.  The latter two products have been developed with more of an eye on ease of use (development and maintenance). MySQL is virtually a free product and powers many modest web sites that have a data requirement.

How are enterprise level databases used for residential property applications?

One of the obvious uses for powerful data processing is the requirement of the major property portals.  For example rightmove, fish4homes and probably many others all use Oracle. Here there are vast numbers of people conducting complex property searches 24 hours per day - an ideal application for an enterprise level database.

For agent software systems however the use of enterprise level databases is much less common.

Amongst the Windows based systems there are now a few products that use SQL Server to offer the facility for live data across remote sites through their client/server architecture (for more information please click here).

Dezrez, Viewpoint and some of the other recent web based offerings use SQL Server so that they can store several different customer's data in the same database restricting access to the correct data by means of login authentication over the Internet. Dezrez has a hybrid architecture where some data is held locally in Microsoft Access files. Apart from the development and hosting costs this architecture has the potential to be very profitable due to the economies of scale that can be accrued. There is very little extra cost involved in adding extra customers to an existing database. This design, however, would probably not be appropriate for large amounts of financial data like that held for client accounting.

The third model using an enterprise level database would be that of Aspasia where the use of Oracle permits different distinct databases to run concurrently on the same machine.  The fundamental difference to the previous architecture is that all customer's databases reside in their own Oracle "instance" completely separate from each other. An enterprise level database is essential to be able to deliver a software application via the Internet on an ASP basis.

The Aspasia model is also different wherein it uses the sheer power of the Oracle database to create an entire multifunctional product in one database.  Aspasia already integrates residential sales, residential lettings, client accounting, property management, financial services and holiday lets in one large product that can be used in a combined fashion or individually by any one or two business elements.  Commercial sales and lettings will soon follow.  This type of product could not be created with a desktop database engine.

Summary of advantages

For client/server and web based solutions:

• Ability to use live data.
• Central management of data.
• Security, robustness and scalability of data.

Additionally, for most web based solutions:

• Ability to operate with no client software whatsoever.
• Minimal IT support costs.
• Ability to interact with customers via the Internet.

(For information: Aspasia does use an enterprise level database)