Database Server

This is the most typical user of server technology in client server applications.  If not all, most of the applications are run on the client.  The DB server accepts request for data, retrieves the data from its database (or makes a request for the data from another node) and passes the results of the request back to the client. The Compute servers working with data servers give the similar functionality.By using a combination of data and compute servers or a database server, the data management functions on the server and the client program consists of application specific code as well as presentation logic.  Since the database engine is divided from the client, the drawback of file servers disappear. The Database servers can have a lock manager, multi-user cache management and scheduling and therefore have no requirement for redundant data.

Data compute and Data base servers improve request handling through processing a SQL client request and sending return to the client only the data which satisfies the request.  This is much more efficient in words of network load than file server architecture, whereas the complete file is frequently sent from the server to the client.

Since SQL permits records to be processed in groups, an application can, with a single SQL statement, modify or retrieve a group of server database.  Older database system has to issue separate sequential requests for every desired record of each of the base tables. Since SQL can built a results table which combines, filters, and transforms data from base tables and considerable savings in data communications are realized even for data retrieval.

The needs for these servers are a function of the size of the database, the speed with that the database must be update, the number of users and the categorized of network used.