Databases Reference
In-Depth Information
Chapter 2
A Developer's Overview
You're probably anxious to get started, but there are a few concepts that you should understand before you jump into
APEX development headfirst. This chapter introduces the fundamental development architecture of APEX and then
walks you through the different areas of the developer interface.
You delve deeper into the details as you go through the topic and put the architecture to work for you, but it will
help tremendously to know how things are structured ahead of time. This chapter is designed to ease you in, but it
isn't a complete guided tour of every nook and cranny. Be patient; you'll get there.
The Anatomy of a Workspace
APEX was designed from the beginning to be a multi-tenant architecture where many different development
environments (called
workspaces
) can exist in a single APEX instance. For instance,
apex.oracle.com
,
Oracle's free
hosted instance, holds over 10,000 active workspaces, each of which is a completely separate environment unable
to see or interact with any of the other workspaces. You can think of this as Software as a Service (SaaS) or a cloud
computing architecture, but basically it means each workspace is distinct and segregated from all others.
In the simple terms, each workspace represents a virtual private container in which developers create and deploy
their APEX applications. The development process takes place in the context of a workspace, so it's important to know
how a workspace is structured. Figure
2-1
uses database entity-relationship diagram parlance to help explain the
makeup of the objects in a workspace.
Workspace
Parse as
Users
Applications
Schemas
Figure 2-1.
Logical makeup of a workspace
A workspace may have
One to many users:
These users may one of three types: Administrator, Developer, or End User.
Zero to many applications:
Applications can be added from the list of packaged
applications, imported, or created from scratch.
One to many schemas:
Although a workspace must be assigned at least one schema when
it's created, an Instance Administrator may assign multiple schemas to a workspace.
