Ardent Performance Computing
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Accessing Arbitrary Ancestors in Hierarchical Queries
Last Friday I wrote about a client query that could be rewritten in a much more optimized manner. However rewriting it was a little tricky, involving a hierarchical query and a column that needed to calculate a value based on it’s parent, grand-parent, great-grand-parent, etc. Raj posted a very smart solution that used sys_connect_by_path to … Continue reading
Encyclopedia Spine Problem
Dominic just posted a hint to the encyclopedia spine problem he posted last week. Sheesh… personally I think the hint totally gave it away. Or at least it gave away one solution. Here’s what I came up with. I wonder if this is how Dominic solved the problem:
Combining Hierarchical Queries With Analytics
Just a few days ago I was reading Dominic’s challenge to write a query that would give results like an Encyclopedia Spline. It apparently took over the entire day for another Dominic and I was planning to take it on myself too as soon as I had the time… but today another challenge came my … Continue reading
Doug Burns on Oracle User Groups
Just read Doug Burns’ interview from the Autumn 07 edition of AUSOUG‘s Foresight magazine. It’s a fun read; Doug talks about how he got into technology and Oracle, the strengths and weaknesses of the Oracle RDBMS, and his addiction to the command line. But the part that jumped out at me the most was his … Continue reading
Chicago Oracle Users Group Meeting
So we just had the spring COUG meeting. Two speakers this time, Charlie Garry from Oracle and Dean Richards from Confio. Oracle volunteered a meeting room; their offices are in the Sears Tower downtown. They also provided food. (Very cool!) Toward the end – after 5 or 6 people took off – I counted 24 … Continue reading
Controlfile Recovery WITHOUT Resetlogs
Well last week I had a few posts about controlfile recovery; one about recovering without a backup and one about recovering with a backup using RESETLOGS. In the second post I showed how when you restore a backup controlfile Oracle will always require you to recover then open the database with RESETLOGS. Hemant Chitale pointed … Continue reading
Redo Log Filename Extension
I have to say that I really like the oracle-l mailing list. It tends to stay pretty focused on DBA stuff, there’s a low volume of spam and there are a lot of really smart guys who post there. I was just catching up on some threads from last week and a comment about how … Continue reading
Fidelity Case Study
So I guess this is old news since they finished this implementation back in June last year and even presented at Open World. But this case study is just a goldmine of information and totally worth reviewing if you’re anywhere close to RAC, Data Guard, ASM, RMAN, or Flashback (and more I’m sure). The big … Continue reading
Controlfile Recovery Requires RESETLOGS
In response to a small discussion on the oracle-l mailing list last week I thought I’d put together a quick demo of exactly what I was referring to in my email. Basically I was discussing how even when you do a normal shutdown – leaving your database in a consistent state that doesn’t require recovery … Continue reading
Recovering Your Controlfile Without a Backup
Little trick I’d seen once that might come in handy for someone. Lets suppose that somehow you accidentally delete (“rm”) all copies of your current controlfile – and you don’t have a backup!! If the database is still running then don’t shut it down! There might actually be a way to recover the control file. … Continue reading
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contact: schneider @ ardentperf.com
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