role based security, number of connections to Oracle etc -- question on understanding

Hi, I have a design question about the number of connections in an Oracle database.

We have a 10g database running RH, 2G Ram, dual XEON2.6GHz, with about 520 users on a single site. All users have Oracle database roles, some more roles than others, and some roles have more privileges than others. Some database tables have read access for some roles, and other roles have update and insert access. So simple stuff so far.

Some users use client-server applications written in MS Access and have a 1:1 connection with the database instance.

A new system is being put in place, written in .Net, to slowly replace the MS Access code. Both applications work in tandem and will be for the next year.

I don't have access to all the code and, as a mere developer, have very restricted access to the database to query the number of users connected etc.

In the new system users type in their username and password, press the "login" button, and after a second or two the browser window updates with something else. In the code executed when users press the "login" button, a web method is called containing the users Oracle username and password. The web method returns an instanceID. The instanceID is positive if the username and password were valid. The instanceID is negative is if was not. A typical instanceID is 1147501755.

In this middleware, if you want to retrieve an employee, you call the web method with the instanceID and the employeeID. For example .getEmployee(1147501755,'MJONES'). To update the employee first name I would call the employee setFirstName method, eg employee.setFirstName('Margaret'). To update the last name I would call setLastName, eg employee.setLastName('Jones'). To save the employee I would call the save method employee.save(1147501755). The actual code that performs the database update sits behind the web method and all I use is this API.

If the database roles allow me to save the revised employee details, it saves it. If the database roles do not allow me to save the revised employee details, I get an error. If the database roles are changed on the fly to allow me to update the employee table, I repeat the process (without logging on again) and I do not get an error.

Here is my question. Does this all mean that for every user connected using the new system (ie the system in a browser not the old system with MS Access), there is a connection to the Oracle instance? Does this mean that if 520 users connected at once using the new system there would be at least 520 connections to the Oracle database? And is 520 users a lot or could this be done in a better way.

Thanks
Mark Received on Sat May 13 2006 - 02:41:25 CDT