Sesame Library | What Does 'Client-Server' Mean?

Q&A is a "client-based" database while Sesame is "client-server-based." But what does this mean to someone who's now using Q&A and is contemplating a migration to the coming database product from Lantica Software?

In a nutshell, with Q&A - even in a network environment - all the work is done in the memory and by the processor of the workstation that initiated the action (such as a record search). The computer where the database resides is strictly a "warehouse" or storage area for the data - a place from where any user can access the same information.

The result of this arrangement is that if you want high performance, you need powerful computers at both the server and client ends: At the server end to provide the data to all the users with reasonable speed. At the client end to process the information at a reasonable speed. This means higher hardware maintenance and upgrade costs. With different types of client PCs, you'll see significant performance differences with Q&A from workstation to workstation.

Okay, so you've spent the money and you have powerful computers at all your workstations. What's the big deal? Well, suppose you're away from the office. You want to dial in to your server and access your 100,000 record database over a telephone line. With a "client-based" system like Q&A, in order to perform a search, all 100,000 records must be brought across your 56K phone line before the search can begin - even if you only want to see one record! So, you are relegated to using a program like PC-Anywhere to access your system. This means that a computer at the office must be dedicated to receiving your remote call and acting as the client. It then passes only the screen updates of the result set across the phone line.

What does the Sesame's client-server system do in the same circumstances? In the first place, all processing is done on the server and in the server's memory. The client acts almost like a dumb terminal. It does not need excessive processing power or lots of memory. It only needs the ability to send instructions to the server and display the resulting data. This means that you can have an entire office of low-cost, minimal performance client computers and still access extremely large and complex databases from any of them with essentially no difference in performance. You do have to make sure that the server has enough power and memory to access the data and perform the instructions, but one vs. many powerful computers means substantial hardware savings. For remote access, all you need is a computer that can dial-in to your network. The processing is done at the office. The results are displayed on the remote computer. No additional software. No need for high-speed connections.

That said, what about the user who wants to run Sesame on a stand-alone computer? What special considerations are there for a client-server based system? None! Sesame installs on a stand-alone computer just like Q&A does. One program. One installation. No special setup required. Sesame makes the stand-alone PC act as both the client and the server without requiring any user intervention. If Q&A can run on a given stand-alone computer, Sesame will run on the same PC with essentially equal performance. And what's more, remote access to that stand-alone computer can be accomplished just as if it were a fully configured network system.