I read this post by Laurent Schneider yesterday. In the comment section Tom Kyte already explained what the issue was about, but I’ll expand this explanation a little.
The question was why should the apparently invalid statement below work? I mean there is no such column nor number as “1.x”), yet the statement works ok:
SQL> select [...]

That number in the title is not a joke or an attempt to drag out the pain. However, OraNA has been flooded with ‘8′ posts this week, so I thought it worthwhile to post a quick list of some really nice technical posts I’ve noticed over the last couple of weeks. I was just waiting for a weekend opportunity to clean out my pockets, so to speak.

Oracle has evolved over time to much more than just a plain relational database. One option is to use Oracle as an expensive calculator.
When researching or demoing Oracle, it’s quite convenient to do number calculations directly on sqlplus prompt, especially if dealing with internals where lots of stuff is about addresses and offsets shown in [...]

You will find below an excerpt from my latest publication: the 2^nd edition of Oracle PL/SQL Best Practices. This edition is a complete rewrite of the 1^st edition. I decided that since software is still, for the most part, written by humans, I would create a cast of characters who write the software I reference and critique in this book.

I was once asked a question, why does Oracle change its parameter count during session lifetime?
The question arose from the following observation that v$parameter shows more parameters after you adjust some hidden parameter value:
SQL>
SQL> select count(*) from v$parameter;