Posts by André Araújo
As heralded by Iggy Fernandez and Gwen Shapira, NoCOUG has launched its Third International SQL vs. NoSQL Challenge. Pythian is sponsoring the challenge, so I decided not to take part in the contest. However, I’m still having a crack at the problem just for fun. Here is my first take on it.
Backup jobs can be scheduled in many different ways (crontab, Grid Control, Scheduled Tasks, etc) and finding the log file may be tricky if you don’t know the environment well. Furthermore, log files may also have already been overwritten by the next backup or simply just deleted. An alternative way of accessing that information, thus, may come handy. Fortunately, RMAN keeps the backup metadata around for some time and it can be accessed through the database’s V$ views. Obviously, if you need this information because your database just crashed and needs to be restored, the method described here is useless.
Pythian`s Paul Vallee and Andrew Waitman, Pythian’s owner and CEO, respectively, have an exclusive lunch with Larry Ellison at the Oracle head-quarters in San Francisco, CA. As you have already guessed, Mr. Ellison has personally invited Paul and Andrew as a recognition to an unparalleled heroic efforts by Pythian to motivate and support 42 (forty-two) of its most talented DBAs to receive recognition as Oracle ACEs and ACE Directors, due to their wide contribution to the Oracle and MySQL communities around the world.
A few days ago I learned about this year’s NoCOUG SQL Challenge and decided to to put the gray matter between my ears to work. I’ve been teaching a MySQL course this week and my first impulse was to use my MySQL VM to test my solution attempts. However, I eventually decided to use Recursive Subquery Factoring to solve the proposed problem and had to switch to an Oracle 11gR2, since it’s the only database that implements this feature that I know how to use (are there any others?). I was happy with my solution, but frustrated that I couldn’t run it on MySQL. So I decided to try to make it somehow work on MySQL.
Once again the great Wizards of Northern California have reached out to the community, pleading for help in the deciphering of one more challenging riddle. The second edition of the NoCOUG SQL Challenge has been published and is open for submissions! This time Iggy and his ensemble came up not only with a SQL challenge but also with a brain-bender riddle that must be resolved before you can start coding your solution. Very nice!
Last Friday in the Sydney Oracle Meetup I talked about Oracle Flashback technology and how it helps to reduce downtime. The session generated great interest among the attendees, which led to interesting discussions and many questions about the subject. Some of the questions couldn’t be answered during the meeting so I’ve followed up on them and I’m posting the answers here since they may be of interest for many others.
t’s only one week to go now and the program for the AUSOUG National Conference Series 2009 is out. I’ll be presenting on the first day in Perth (Nov 10th) about Oracle Flashback technology. I’m looking forward to attending the conference in Perth, not only because I’ll be presenting there but also because it’s my first time in Western Australia.
This post originated from a quick discussion we had internally on how to quickly and easily compare schemas between two Oracle databases. I learned about Sheeri Cabral’s post with a quick comparison solution for MySQL databases and I though of using a similar approach for Oracle. I did some testing and it worked quite well. There certainly are tools in the market, free or not, that do this for us, and even generate scripts to correct differences. The steps below only go as far as to tell you what the differences are. However, they don’t require any additional tool and can be easily executed in any *nix or Windows environment.
Have you ever been asked to restore a database and wondered which backup files were available? And if many were available, which ones you should use, and in which order? Okay, this is not a difficult thing to do, but when you do it over and over again, it becomes tedious, and the automation bug in you starts to look for a better and quicker way to handle it. The bug in me found the following answer.
I love puzzles. So when I heard about the NoCoug SQL Challenge I felt tempted to give it a go. The Northern California Oracle Users Group (NoCoug) has challenged us to find a good way to calculate the probability of getting different sums for x throws of a n-sided die using only SQL. The probabilities for the faces of a single die are stored in a table and that’s all you need to start playing with the problem. The SQL Challenge rules can be found on the NoCoug website, along with some other relevant information.