In my last post, I gave a highly simplified representation of “The I/O stack” of a database. In reality, it’s much more complex. I found an old picture where the whole I/O stack of a database was described and I…
The missing link in application performance tuning
When dealing with application performance problems, the quick and easy solution is often to throw hardware at the problem. Typically this is one out of processing power (CPU), memory, or more I/O resources. With a bit of luck, the bottleneck…
POC: Piece Of Cake or Point Of Contradiction?
Every now and then I get involved in Customer Proof of Concepts. A Proof of Concept (POC) is, according to Wikipedia, something like a demonstration of feasibility of a certain idea, concept or theory.
Managing database performance SLA’s with quality of service
A guy walks into the showroom of a Porsche dealer. He wants to buy a new set of hot wheels. The sales guy tells him about the latest technology in sports car design. This year’s model has active 4-wheel drive…
Duplexing Oracle Redo logs?
A customer asked me recently what EMC’s advice is regarding duplexing Oracle redo logs. There is a thought behind this – Oracle redo logs are sensitive to data corruption – if redo logs are corrupt, there is no way to…