|
Client Server databases Advanced Topics: You do not need to understand any of the topics presented below in order to use the CCS Accounting program. They are provided for those who seek a deeper understanding of the CCS data management tools. Major advances have been made in Client/Server Technologies. SQL (Structured Query Language) has been available for years; however developing a program using SQL Client/Server technologies generally could not be cost justified for the smaller PC networks. With the advancements in ODBC (Open Database Connectivity) and the recent release of ADO (Active Data Objects), the process of creating a high end, client/server database is now quite affordable. A client/server topology differs from multi-user, in one very important aspect: the Server (most likely an NT Server) is responsible for the selection/sorting/gathering etc. of the data instead of the individual work stations. This has several major advantages. The primary one is that only information that is actually required by the workstation is sent over the network, thereby greatly reducing traffic over the network. The flow of data across network connections is the weak link in any network, regardless of its topology. For example, in a multi-user environment, a request by the user from a workstation for all EMPLOYEES who have overtime hours for the current week requires the workstation to request from the file server the firstrecord in the time sheet file (assuming no index on overtime hours), to analyze the record for overtime hours, and then to keep or discard the record based on its analysis. The workstation then requests record #2 from the file server, performs the same analysis, and so on until the end of the file is reached. A search of this type is extremely inefficient since each and every record in the time sheet file was sent over the network so the workstation could analyze it with no knowledge by the server as to its intended use (if any). In a Client/Server based network (Using Windows NT and SQL Server for instance), the workstation makes a "structured" request of the file server to "Select" all EMPLOYEES who have overtime hours in their time sheet records. The server then makes the analysis of each and every timesheet record and sends only those records that actually have overtime hours (if any). The only data that crossed the network was data that was truly needed. This of course speeds local area networks considerably and makes Wide Area Networks (WANS) possible. Using Client/Server a workstation can access data from an ODBC data source located half way around the world at speeds that rival that of a local stand alone PC. The new CCS Data libraries are fully client/server capable and are written exclusively using C++ and SQL/ODBC/ADO technologies. Another advantage of Client/Server is that, when a single high speed (perhaps multiprocessor) computer is purchased to perform the duties of the Server, all workstations realize the benefit in performance, since it is the server, not the workstation performing the data access. What does all this mean to you, the user? The new CCS programs are fast, efficient and extremely flexible, working just as well on a single PC, five workstation LAN or a multi-server WAN. Pick the level of data management you need, and CCS Accounting can deliver it.
|