Databases Reference
In-Depth Information
Now, it's impossible for me to say “Always use XYZ, it is the best.” The truth is more likely that the
right choice probably depends on your exact requirements. In fact, this would be a very short discussion
indeed if I could just say that XYZ was always best in all circumstances. So, in this chapter, I will go
through some of the areas that I think are important for the web server. They will include the following:
•
Installation
: How quick and easy is it to get up and running? In some situations
you might not care about making it the most secure environment possible and
just want it up and running as fast as possible.
•
Configuration
: After the initial setup, how configurable is it? What sort of options
can I “tweak”?
•
Extensibility
: Does the web server offer any ways to extend it and add
functionality?
•
Scalability and Performance
: How well does the web server scale? If the number of
end users of my application grows will I need to add more web server or can it
scale up?
These are overarching concepts and I won't rigidly stick to them, but they give you a general idea of
the sort of things I believe are important. Rather than jumping back and forth between the different
options (which could be confusing), I'm breaking the rest of the chapter into three parts to cover each of
the options and show the various possibilities and features provided by each of them.
Web Server Basics
If you have never looked at the Oracle APEX architecture before, it really is a pretty simple and yet
powerful architecture. In the case of the OHS, the web server sits between the web browser and the
database and is responsible for handling the requests from the web browser, passing them through to
the database (via something called
mod plsql
), then APEX processes the request and generates the
response (the HTML code to send back) which is passed by to the browser via the
mod plsql
module in
the OHS. Figure 1-1 illustrates this architecture.
Figure 1-1.
The Oracle HTTP Server architecture
By contrast, when you use the EPG there is no “web server in the middle”; the web browser is
actually connecting directly to the database, as shown in Figure 1-2.
