SQL Snippets ™: Tutorials for Oracle Developers

Today I added the tutorial Serial Numbers to SQL Snippets. I didn't plan on adding this topic until later but I fell into little task spiral. Never heard of a "task spiral"? Neither had I until I made the term up just now. Here's what I mean. It started about a week ago and went like this.

1. I should start working on my taxes.
2. Hmm, I need a list of my expenses. I'll put them all into a spreadsheet.
3. Spreadsheets bite. You know what? I'll slap together a few tables, a data entry form, and a report for this instead.
4. I need a column in my expense table for Invoice Numbers. You know what? I just finished that tutorial on Integer Series Generators. A tutorial on invoice/serial numbers would complement that topic nicely. I've got some notes on the subject somewhere. I might as well tackle it now.
5. O.K. That took a while, but I've finally got the section written now. Hmm, you know what? I only talk about generating a serial number as you need it. Some people do it by precreating the serial numbers instead. I wonder how that would work? Let me give it a shot. It shouldn't take more than a day, should it?
6. (3 Days Later) O.K. that wasn't as simple as I thought, but at least it's done now. I should post it to the site now. You know what? I used DBMS_LOCK in that solution. DBMS_LOCK would make a great topic for another tutorial section. Maybe I'll work on that for a bit and post both tutorials at the same time. Before I get started, I wonder how my site traffic is doing? Let me check the stat counter.
7. HOT CHOCOLATE !!!! People are finally reading my stuff! Hundreds of them! And they're blogging about it too (see Igor's Oracle Lab, thanks for the plug Gary :-) ). Ooops, sounds like Gary doesn't like the fact I don't have an RSS feed on the site. He went and made one himself using some online service. That's the second person to do that. Darn, I've been meaning to work on an RSS feed for a while now. Guess I should get started on that.

8. ERROR at task 8:
   JOE-20000: too many tasks
   
   $ oerr JOE 20000
   20000, 00000, "too many tasks"
   // *Cause: You have too many tasks in your Life Stack.
   // *Action: Finish the tasks you currently have in the stack before
   // initiating any new ones.
   // If error persists, contact a life coach.
   

And that's how I ended up posting a tutorial on serial numbers.

Now, where was I? ...