October 1996
Intermediate to advanced
687 pages
16h 41m
English
Content preview from Advanced Oracle PL/SQL Programming with Packages
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1.2. What Are the Types and Layers of Packages?
Although any PL/SQL package must have the same structure and follow the same rules, there are different types of packages that will play different roles in your application.
| Types of Package | Description |
|---|---|
| Builtin | A builtin package is provided to you by Oracle Corporation, built right into the PL/SQL language as installed. (A builtin package could reside in the database as stored code or could instead be imbedded in a client tool, such as Oracle Developer/2000.) |
| Prebuilt | Prebuilt packages are libraries of packages that are built by third parties or other developers that are installed in and used by your PL/SQL environment. |
| Build-Your-Own (BYO) | The very best kind of package: the one you build yourself, or is built by your application development team. |
Figure 1.1 shows how these different types of packages interact as layers of PL/SQL code and packages that are available to you. We describe the types further in "Types of Packages" later in this chapter.
Figure 1.1. The layers of PL/SQL code and packages
The lowest layer of code upon which you build your PL/SQL applications is the SQL language. PL/SQL was designed explicitly as a procedural language extension to SQL; most of your PL/SQL programs will function as an interface between a user of some kind and the database.
The next layer of code is the core PL/SQL language. At the center of the ...