Beware the hidden parameters... magic comes at a cost!

I was reading a series of posts on Oracle-L which had to do with a database that would not come up due to undo tablespace corruption.

http://www.freelists.org/archives/oracle-l/04-2008/msg00821.html

There are some undocumented ways to respond to undo corruption. An example of one way is mentioned in the following blog (you can find this solution many places, but this is just one example I found):

http://priyambodo.blogspot.com/2007/03/oracle-undo-tablespace-corrupt-in.html

(note there are other solutions for other specific conditions, but the same basic principles exist - I also have not taken painstaking measures to review the technical content of this blog entry, so use it at your own risk!!).

Now, the point of this post is this. The magic UNDO solution suggested here, using hidden parameters is all well and good, you might well get your database open again. I've been in places where this method was used just fine, and the database opened.

Unfortunately, afterwards folks didn't want to consider the potential negative ramifications to the database having used this method. What is the problem you ask? Well think about what UNDO is all about. Undo is the before image of a block that has been changed. It's used during recovery to rollback any uncommitted changes. The implication here then is that your data may well be inconsistent after you open the database using the method outlined above.

Want more? Think about the system tablespace and the Oracle metadata. IT used UNDO also, and so the SYSTEM tablespace data may well be inconsistent. Thus, you essentially have a corrupted SYSTEM tablespace. Not a good situation.

So, if you are going to use this big hammer, consider these implications. What I'd do is if you manage to get your database open, use exp or expdp to do a backup, recreate the thing and then load the data into the database. Your data may still be corrupt, but at least the system tablespace will be pure.

You can go fix your own data yourself.

Finally, this can all be magically solved if you introduce a sound and TESTED BACKUP STRATEGY before you have the failure. If you have a sound backup strategy I can almost assure you that you will never run into this kind of situation.

Oh yeah, I wrote a book on just that topic, backing up your database with RMAN....

http://www.amazon.com/Oracle-Database-RMAN-Backup-Recovery/dp/0072263172/ref=pd_ts_b_9?ie=UTF8&s=books

I have HAD IT!!! And I'm not going to take it anymore.

Ok... time to vent. I like to read. Magazines are among my favorite form of reading (I like science magazines, airplane magazines, train magazines, financial and the like). I like them because the information is generally current, up to date and always interesting.

But I'm SICK AND TIRED of this.... I'm reading in my favorite magazine. I turn the page, and this STUPID CARD comes flying out and lands on the floor. With each stupid magazine maybe 2-4 of these buzz bombs falls out. This is IRRITATING to me. Not only is it irritating when they just fall to the floor and mess it up, but I like to sit in my bath and read from time to time too... so then the cards get wet. Plus it's just killing more trees.

So, I have a plan. I think we should all take these cards, shred them up and then send a bulk set of them to each publisher once a month with a letter that says, STOP PUTTING LOOSE SUBSCRIPTION CARDS IN MY MAGAZINE!!

Does anyone hate this as much as I do?

Collaborate and Clifford...

I've been working on my Collaborate University Session which is coming up in 2 weeks!! If you have any interest in 11g, it will be a good introduction to many of the new features in the product. I will be doing lecture and a lot of live demo's. I'm working on the live demo's for AWR right now.

If you have read one of my books you may have read about Clifford. Clifford is not a big red dog in this case, but an old (12+ years), cranky fur ball who I just love to death and somehow manage to get along with.

You see... my history with cats, and that of our family, is checkered. Not that I'm mean to them in any way, but I've never been a big cat fan to be honest. The truth though is that cat's never faired well in this family. There was Snowball who just died... then there was Fred who we lost somewhere between Oklahoma City and Seattle.

Then there was the day I got a call from my ex-wife.... she was crying, and I asked what happened. She said that she had gotten in the car and started the engine. All of a sudden, from under the hood of the car was this poof of fur and a ker-tump. It was cold, the cat wanted to be warm, and you can imagine the rest. Unhappy kids that day I can tell you.

Then there is Fonzie, who is our other cat. Fonzie has had her own close calls, including crawling up in the engine of the car of one of my kids friends. Fonzie got singed, burned and humbled but survived.

Then, there is Clifford. The old man of cats. Clifford sits on my feet, keeping them warm. He growls at Fonzie, making sure that Fonzie is clear on who is the senior animal in the house. Clifford stalks invisible prey (as does Fonzie). Cliffords nemesis is Denali, who is this harmless black lab/Shepard mix. Denali wants to make friends... Clifford doesn't trust Denali any farther than he can meow at her. Clifford will steathly stalk around Denali... watching carefully for some subliminal sign of impending attack. Of course, the only attacking Denali is likely to do is a lick Cliffords face off attack, but Clifford does not seem to understand this.

Hey, he keeps my feet warm! Here are some pictures of Clifford. This is one with him curled up under my desk, snoozing away. Lazy cat!!



Here he is under my wife's desk.... silly cat...

N7598U goes in for it's annual checkup!

So, my Cessna 150 (I own two airplanes, the other is a Mooney M20) is going through it's annual ...

Jared and I went to the airport last Saturday and with our A&P Roberto we opened up all the inspection panels, tore out the interior and so on. That took about two hours or so!

Today Roberto did the inspection of the fuselage which turned out great. I thought I'd share a few pictures with you...

Here is N7598U from her port side. Note the ladder holding up the back end. This was because my son Jared was in the back pulling out all the inspection plates and interior... He's heavy enough that when he's at the back of the airplane it would tip!!



This is from the interior of the airplane looking back towards the tail section. Perhaps not exciting... :-)



Here is where I am usually sitting.... seats and carpet removed for inspection ...



DIRTY CARPET!! Needs replaced badly so I'm going to see if I can't find some...



Roberto my trusty A&P mechanic doing the annual!!



Ok, so this isn't related to Oracle Database 11g but there you are, proof that my life is about more than Oracle!

Collaborate commith and Battlestar Galactica - I'm depressed!

Has it really been almost a month since I've done an update on this blog!?!?!? Wow. Well I've been busy getting over my foot killing me, then the flu and now my knee is killing me. I swear, I'm falling apart!!

I'm also busy preparing for Collaborate '08. I'm doing a University session on Oracle Database 11g New Features. If you have not signed up yet, now is the time!! In the session I will be talking about upgrading to 11g, and highlighting and demonstrating a number of the new features out there. The University sessions are not that expensive and this session will be a great way to get some exposure to 11g!

However, I must confess that I'm a bit depressed about it all too. One of my passions of late is Battlestar Galactica and it's music. I love the music that Bear McCreary does for the series (as poor Lisa can attest too). Bear does a concert every year, playing the music from the series live.. I wanted to goto this thing last year but could not. I just noticed that he has setup this years concert on April 13th... which is the day I'll be in Denver doing my University session. WHAAAAAHHHHH!!! Maybe I can go next year.

Bears music is a great combination of in your face raw music and lighter, sit down and relax music. If you get an opportunity to listen to the soundtrack of season 3 of Battlestar you will not be disappointed. Here is an example that is on YouTube right now... It's called Prelude to War and it's one of my favorites.






Finally, we are doing the annual on 7598U right now. I'm going to goto the airport and take some pictures of the bird now that she's all opened up. I'll post those shortly.