What is this "testing" thing?

Recently asked on the OTN PL/SQL forum:

I am reading a book: Learning Oracle PL/SQL by Bill Pribyl and Steven Feuerstein.

I am a newbie of PL/SQL and I got no other programming XPs. but in the very first of this book they are introducing something called: testing, to make some test programms /utilites.

I found that is very hard to make, is it neccessary?

Apparently, after you've typed the final semicolon, you can either sit back and open a beer with the satisfaction of a job well done, or you can check whether the thing works. And apparently it's hard, so, do we really have to?

Well, another poster was recently arguing that PL/SQL is not suited to unit testing anyway, or refactoring either for that matter, because it isn't object oriented. I think that will be my excuse from now on. You want me to test stuff, go make PL/SQL more objecty.

Welcome back

Our guest administrator "Splogger" has now left the building, along with his page of helpful links to items on Amazon.com and a range of gentlemen's health products.

Suspiciously, a couple of days before he arrived we were taken off air by Blogger's spambots, presumably alerted by the amount of irrelevant, repetitive, and nonsensical text and links to Viagra sites they found here. From what I read, it seems possible that the Blogger automated suspension to prevent blog spam might have actually left the account vulnerable to blog spammers. As ironies go, that is up there with rain on your wedding day and good advice that you just didn't take.