What were the main disadvantages of CGI-BIN based web development?

I was fortunate enough to not do any cgi-bin .cgi based web development. But generally those who have do not seem to 'miss' those days.

A project I recently joined has a performance issue when dealing with the pages that need to communicate to a legacy system that has a CGI-BIN based API. That system is COGNOS 7.

The feedback I received to date is that 'COGNOS is slow' but others have reported great success with COGNOS, I am thinking it has more to do with the access via CGI-BIN and not the performance of COGNOS in and of itself.

All that said what are the main issues that made CGI-BIN based web development non-performant, difficult, etc...

Solution

The fundamental architectural issue with CGI-BIN based systems is that each HTTP request requires the server to start a new process. This affects performance in a number of ways:

It's expensive to start the process, as the OS pages in the program, sets up the process, etc.
Resources can not be shared across requests, so that any DB connections, etc. have to be set up with each request
User session state can not be preserved in memory, so it has to be persisted with each request