Posts by Christo Kutrovsky

Metalink Note on Datafile Recovery Will Corrupt Database

Thinking I had something new, I wrote this article about recovering deleted files. However, it turns out Frits Hoogland had already blogged about recovery of deleted files on linux, as Frits pointed out in a comment on my blog, where he also mentioned a metalink note on this matter. The procedure outlined in the note describes how to recover the deleted file and put it in the same location as the deleted file. The problem is that it doesn’t include offlining/onlining the file, so the database ends up with two distinct copies of the file.

How Will 11g Change Oracle Datacenters?

Let’s focus on what 11g is all about. The main message I got is that Oracle 11g is the consumer release. According to Mr. Phillips, what this means is that Oracle has listened to its clients and has worked in the areas that the consumers needed the most. The fact that Ari Kaplan, the president of the IOUG, was on stage during the launch speaks for itself. As for what’s new in 11g, three major features come to mind…

Using Block Dumps to Read Uncommited Transactions

My team and I still use old-style rollback segments for one of my client’s 10g production databases. We just never found the need to switch to automatic undo management. There are a number of 1GB rollback segments. They are that size because they need to be able to support large transactions. At the same time, we don’t want to have transactions bigger than 1GB as this is an OLTP system. For the past few weeks we’ve had a strange problem. One of the web calls would cause one of the rollback segments to become full by using 1GB of undo data.

Oracle 10g Transparent Encryption: Not So Encrypted

I had been asked by a client to try out Oracle 10g’s transparent encryption. I’ve created the wallet, set it up into the sqlnet.ora file, and opened it. I initialized the certificate, created a test table, and encrypted a column with it. Maybe you’ve done the same, and thought, “now my data is safe and encrypted”. Are you sure? Did you check? I did. And here’s what I found.

Beta-Testing Oracle 11g

Let me tell you the story of the on-site beta testing of Oracle 11g, where success is measured by the number of times you caused Oracle to misbehave. And let me tell you, it’s very hard to do so, even in the beta. It takes a specific mindset and a bit of adjustment to get in the mood to make things not work.

Pythian Activity at Collaborate 07

This year, there are three Pythian employees (Christo Kutrovsky, Alex Gorbachev, and Babette Turner-Underwood) going to Collaborate 07. All three of us ( will be presenting from the IOUG side. We provide our abstracts and presentation materials here.

Oracle Clusterware Install: “Invalid parameters”

So, you just installed the Oracle 10g clusterware, you just ran and got an error, you just went to metalink Note:316583.1 or Note:387691.1 the given interface(s), “eth0″ is not public, public interfaces should be used to configure virtual IPs, it just failed, and now you are relying on Google to help you with what Metalink couldn’t. Well look no more, and here’s the solution.

Aligning ASM Disks on Linux

Linux is a wonderful operating system. However there are a number of things that one needs to do to make sure it runs as efficiently as possible. Today, I would like to share one of them. It has to do with using ASM (Automatic Storage Manager) disks.