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Oracle PL/SQL (Procedural Language/Structured Query Language) resources, news, and support articles.

The Last Post on This Blog (for all the right reasons)


I have used this blog to make announcements regarding the PL/SQL Challenge since April 2010.

We had a great run, and now we can look forward to a greater future, as the PL/SQL Challenge is now an Oracle website:

And that's not all: we now have an official blog at the official Oracle blogsphere:

So all future announcements will happen there.

A natural born tree right in my own backyard!

As some of my readers may have noticed, I spend a lot of time these days among trees, paying attention to trees, cutting back invasive trees to save native trees, etc.

And one thing that I came to realize is that at least in an area like Chicagoland, humans tightly control the reproduction of trees. 

MATCH_RECOGNIZE: matching based on aggregates

The heart of row pattern matching is finding which row matches what part of the pattern. Within the 12c MATCH_RECOGNIZE clause, DEFINE lists the conditions a row may meet; it doesn't always work the way you expect, especially if you use aggregates in the condition.

Mac SQL Developer Install

This how you install SQL Developer on Mac OS Yosemite. The first thing you need to do is download and install Java 8, not Java 7 on your Mac OS Yosemite, as suggested on some web sites. You can determine whether or not Java is installed by running the following command:

Deadlock with a Virtual Column

Virtual Columns are really cool. I like them a lot. If you've never heard of them, shame on you, learn about them.
In short: a Virtual Column is not a real column, it's an expression that looks like a column... more or less.
While using the Virtual Columns, we ran into a little oddity with them.

Feasibility survey of a possible European Kscope-like conference

As most people likely to read this blog will know, I am a great fan of the ODTUG Kscope yearly conference for Oracle developers. In my opinion it is one of the absolute best places for awesome content, presenters, attendees and networking - all wrapped in one high quality package that's fun too.

Merging Overlapping Date Ranges with MATCH_RECOGNIZE

I forgot to add a MATCH_RECOGNIZE solution to my last post on merging overlapping date ranges! That should take me just a few minutes, right? Wrong: it’s not that easy and here’s why. For test data, please refer to the previous post. To Merge or not to Merge? The idea is to merge date ranges if […]

PL/SQL Challenge Website Joining Oracle!

When I (re)joined Oracle in March 2014, the PL/SQL Challenge website was also acquired by Oracle. I'd been thinking that in a few months or so, we'd have it up and running on an Oracle server, re-branded with lots of red.
But then, well, I got kind of busy with all sorts of other stuff. My bad.

Run X11 Apps on Mac

It’s possible folks didn’t notice but Mac OS X no longer includes XQuartz by default from Maverick forward. You need to download XQuartz and install it. I’d recommend after you install Xcode.

Launch XQuartz and then either use the bash shell it opens or open a Terminal bash shell session. Inside the shell, you might start Secure Shell (ssh) like this:

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