Tag: DBA Lounge

ZFS – VM for Storage?

James Foronda sent a link to his blog entry about silent data corruption in an Oracle-l discussion. He points out a new file system called ZFS that has self-healing features.I read all the slides and it really looks like something cool to try out. It has some features similar to Oracle’s ASM, such as dynamic adding of disks, self balancing etc. It’s fully transactional, supports snapshots, online everything. Auto striping (not sure how this would work). Very feature rich.

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Oracle 10g R2 RAC – vip on wrong interface

I was installing RAC, and during the clusterware install I picked up the wrong interfaces for public and private. What had happened was I had a 10.x.x.x IP on both eth0 and eth1, which was messing up the routing. The solution? Simply modify the VIP in the cluster configuration.

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Oracle: Deleting Duplicate Rows Efficiently

Finding duplicates with RANK – If you’ve made the mistake of forgetting a primary key on your table, it can be frustrating to find a way to delete all of the duplicate rows without deleting the initial instances. This query selects all of the ‘extra’ rowids and removes them.

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Collaborate 2006 Presentations

Well I have been back from Collaborate 2006 for over a week now and decided that I should also make my presentation available from the Pythian web site. While there I participated in three sessions. I joined Michael Abbey, Ian Abramson, and Carl Dudley on a panel for the Non-Oracle DBA. My first presentation was PostgreSQL for the Oracle DBA. My second solo-presentation was Oracle 10g Data Pump 101.

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ASM multi-disk performance

If you have the ability to combine disk spindles at both the SAN level and Oracle (ASM) level, which one is better? Should you combine all your spindles on the SAN and present 1 big disk to OS and give that to ASM? Or should you present each individual disk spindle to ASM and let ASM do the mirroring? The disk group with 2 disks is slower! Those results are consistent, and confirmed with diagnostic output from iostat. You may start to wonder why would 2 be slower then 1. It should be twice as fast!

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IT Industry Trends Towards Anti-Certification

Did anyone else notice this interesting e-week article titled The Downside of Certification? It immediately reminded me of an article written by Pythian team lead and datawarehousing architect Rob Hamel titled “Get Down with OCP: Evaluating DBA Job Applicants in an OCP World”. What Rob noticed in 2004 was that certification can mask a certain type of incompetence from a casual technical evaluation process.

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Oracle Finally Documents lnnvl() in 10GR2

Tip of the hat to Eddie Awad who does some noticing and some digging to confirm that lnnvl(), a function that provides functionality similar to ANSI “Is Not True” and can be used to return boolean TRUE whenever the predicate to the function is either NULL or FALSE is now supported in 10GR2.

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Silly DBA Tricks 1: Editing the SPFILE

Here is an article I posted on the Oracle-L mailing list recently. Much to my surprise, people liked it enough that they asked to see it here, too.
This was written in response to the question: “How do you edit an SPFILE?”

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Day two at Collaborate 2006 (Babette)

I skipped the general session but heard there was talk about Oracle unlimited support. Basically someone else summarized it as Oracle will take your money as long as you want to give it to them. So no more “de-supported” products. Of course, old products will not get bug fixes unless you really really really pay for it.

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UKOUG Northern Server Technology Day

Good luck to acquaintances (dare I say friends? we have never met in person!) of mine Jonathan Lewis and Doug Burns who are presenting on April 27th at the UKOUG Northern Server Technology Day.

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