Correlation names are alternate names given to tables in an SQL command. Sometimes correlation names are required. Other times they are optional, but helpful. I would go so far as to say that it is good practice to use correlation names as often as possible, even when they are not obligatory. Let me share two good reasons to do so.

But first, let’s review the basics of correlation names. A correlation name follows a table name in the FROM clause. The table name and correlation name must be separated by white space. You may also include the filler word AS

Eons ago, IBM enhanced the RPG compiler by allowing program-described files to define data formats using data structures instead of Input and Output specs. I have taken advantage of this ability from time to time since then, and would be willing to testify in anybody’s court of law that I don’t miss I and O specs one little bit. It was much later, in V5R2, that IBM decided that data structures should be allowed for externally described files as well. I was not so excited about this decision until recently, when I realized that the use of data structures for

I’ve recently been involved in a high availability (HA) project where the goal is to be able to switch processing from a failed System i box to a Capacity Backup (CBU) machine within one hour of failure. Growing from that experience, this week’s column is the first of an occasional series where I’ll discuss HA concepts and how i5/OS administrators can expedite continuous availability procedures in their shop.

What Does High Availability Mean To a System i Shop?

Although there are more complicated definitions for high availability, my favorite explanation is that high availability consists of whatever you do to