Some time ago, in an article entitled Developers Don’t Despair: Virtualize Your PC, I listed the benefits of using PC emulation software such as Microsoft‘s Virtual PC or VMware‘s VMware Workstation.

In particular, I discussed why an IBM i specialist may find using a virtualized workstation helpful. These terrific products allow users to create a variety of operating system (OS) and software configurations without having to buy or revamp existing hardware. Best of all, the VMware Workstation is relatively low cost, and Microsoft’s Virtual PC product is free.

As a brief reminder about Virtual PC, if you

Please settle a disagreement. Another developer claims that it is bad to use an SQL subquery if the same results can be achieved with a join. He says that database management systems can optimize joins better than they can optimize subqueries, which means that joins run faster than subqueries. Is this true? I seem to have heard somewhere that the query engine converts a subquery to a join when possible.

–Dee

If the other developer is experienced with database management systems other than DB2, than he may be correct. However, when it comes to DB2 for i, you are correct.

Being a robust system developed over several decades, i5/OS has several valuable features that you may not be aware of. For example, the Application Administration function allows you to provide and deny access to many sensitive system functions. This week, I’ll look at Application Administration and demonstrate how it can help you obtain better control over what your users can and cannot do on the system.

What is Application Administration?

Application Administration is an optional plug-in for iSeries Navigator (OpsNav). It allows you to view and customize the following client- and server-based applications and functions associated with i5/OS processing:

• iSeries