Why PLSQL?

Why PL/SQL?

Now that the fundamentals of how the PL/SQL Web Toolkit functions have been discussed, the logical question to ask as a developer is, Why would I want to use PL/SQL for web development? While it s not appropriate for every development circumstance, there are many good reasons for using PL/SQL and the PL/SQL Web Toolkit to develop your web-based applications. Two major considerations are the scope of the web application and the talent pool within your organization available for its development, deployment, and maintenance.

While PL/SQL is good at pushing HTML out and very good at manipulating data stored in an Oracle database, scalability can sometimes be an issue. When developing an application using the PL/SQL Web Toolkit, the application server becomes, essentially , a pass-through server ”that is, a server that does nothing more than pass requests back and forth between the client and the database. The HTML that is generated using the PL/SQL Web Toolkit is work performed by the Oracle database, which also must carry out its normal data processing duties . In this environment, the Oracle database server is now doing work that would ordinarily be carried out by the middle- tier web application server. This may not be a problem in a small- to medium- sized application scope, but in a large enterprise web application, a database server experiencing a heavy load servicing data requests must now also make PL/SQL function calls to generate HTML, a nontrivial task.

The PL/SQL engine in the Oracle 10 g database has been upgraded and now incorporates many new performance-enhancing features. Both Oracle Portal and HTML DB use PL/SQL extensively and have references of extreme scalability. In a Real Application Cluster (RAC) environment, additional performance gains are realized through Oracle s capability for each node in a cluster to execute PL/SQL simultaneously .

Using the PL/SQL Web Toolkit also takes server clustering at the middle tier out of the equation of system performance considerations as well. In larger enterprise environments, a traditional architecture incorporating J2EE technologies ”including JSPs, Oracle Application Server Containers for J2EE (OC4J), and Enterprise JavaBeans (EJBs) ”may be a better option, as the burden of generating the front end of the application is shifted to the application server. In recent years , a significant effort was undertaken to improve the performance and scalability of J2EE applications. However, a similar effort has not been undertaken for PL/SQL web application development. It is the developer s responsibility to carefully consider the current and likely future scope of an application to make sure the PL/SQL Web Toolkit makes sense.

Along with considerations of application use and scope, factors focusing on the skill set of developers needed to develop and maintain the application need to be addressed. The PL/SQL Web Toolkit is a good fit for organizations that already have PL/SQL expertise, but lack the equivalent expertise in Java. Use of the PL/SQL Web Toolkit is appropriate if the scope of the application is relatively small and will be primarily used internally. In this scenario, requisitioning outside Java talent or training existing employees in Java, both of which can be financially prohibitive, can be avoided.

In the spectrum of computer languages, HTML is easy to learn, so with a minimal amount of study and training, PL/SQL developers can be easily tapped to develop web applications using the PL/SQL Web Toolkit. PL/SQL server pages (PSPs), discussed later in this chapter, can be used to partition the task of writing HTML to people within the organization that specialize in web front-end design and development, leaving the PL/SQL developers to the task of writing code.