DBA Lounge

One of our more stable clients had some serious “mystery” production problems. To paraphrase, their app that was running “OK” starting running “sucky”. I knew that nothing had changed from our end and so being the intrepid super-sleuths that we are, we determined that the problems were related to I/O.

If you are using Oracle Data Pump to backup tables containing LONG or LONG RAW columns, then you might be surprised when trying a recovery. Well, you tested it already. Didn’t you? ;-) Right now I’m in the middle of a production migration. Earlier this week while testing this migration, I noticed couple strange errors during Data Pump import:

While testing a migration, I figured out that schema export using Data Pump doesn’t capture public synonyms on the objects in this schema. Does anyone know how to make Data Pump include public synonyms with schema export? Update: This is actually the same behavior as old Export utility.

This will help when you need to investigate some past changes to your database when auditing was not enabled. This doesn’t imply that you don’t need auditing. On the contrary, I see no reason not to use it in any and every database. However, often we get systems “as is” and we need a working method now and not the next time it happens.

As I was poking around metalink, I found the following extremely interesting section. It’s in a very obvious place, but it’s new, so many of you may have not noticed it. It’s called “Support case studies” and provides some amazing articles.

When I read Note: 391116.1 with the full list, I noticed the following bugs that we’ve encountered are fixed. Unfortunately, an important bug in 10.2.0.2 posted on the Sept. 29 is not listed as fixed in this patch list.

One day I came up with the following neat idea. Start a second listener, on a different port, calling it the emergency listener. Then renice the listener process with higher priority. Now, every time I connect to the database via my emergency listener, my connection gets higher priority, and thus feels like there’s no problem with the database’s resource use.

There is one little caveat however. You need to either have access to root, or have a nice SA that will add renice to your sudoers file .

I have submitted an abstract for my new presentation about linux/unix memory and Oracle to the Rocky Mountain Oracle Users Group for the Training Days in Denver on February 14-15, 2007. I pilot tested it at the Ottawa Oracle User Group in June. The feedback was good and since then I have kept developing the presentation. Soon to be submitted for HotSos 2007.