I ran some SLOB tests over the weekend using the new SLOBv2 kit and noticed some interesting results. I was using SLOB to generate physical I/O but the "anomaly" is best demonstrated by putting SLOB in "Logical I/O mode", i.e. by having a large enough buffer cache to satisfy all reads. I'm calling SLOB with the … Continue reading SLOB: PL/SQL Commit Optimization
Category: Databases
Databases are the systems of record at the heart of the enterprise. They were designed for correctness, durability, and human-paced interaction – not for continuous, machine-driven access patterns.
As workloads evolve, the database remains the point of truth… but the assumptions around how it is accessed are starting to break.
SLOB2: Essential for Every DBA Toolkit
A couple of weeks ago, Kevin released the second version of SLOB - the Silly Little Oracle Benchmark. Readers will know that I was already a big fan of the original version, but version 2 (which I was fortunate enough to test prior to its release) now has extra features and functionality which make it … Continue reading SLOB2: Essential for Every DBA Toolkit
Does My Database Need Flash?
Not every database benefits from flash storage – knowing when it matters requires understanding how much I/O your workload generates, how random it is and how much latency is already costing you.
Understanding I/O: Random vs Sequential
Disk I/O forces a choice between random and sequential access – and that choice defines whether latency compounds or disappears. Flash makes the distinction irrelevant.
Strange ASM Behaviour with 4k Devices
This is only a short post to document something I've seen and reproduced but still don't understand. Storage devices generally have a physical sector size of 512 bytes or, more recently, 4k. This is a subject which causes much confusion (partly because some vendors seek to portray whichever sector size they use as "better"). You … Continue reading Strange ASM Behaviour with 4k Devices
AWR Generator
As part of my role at Violin I spend a lot of time profiling customer's databases to see how their performance varies over time. The easiest way to do this (since I often don't have remote access) is to ask for lots of AWR reports. One single report covering a large span of time is … Continue reading AWR Generator
Engineered Systems – An Alternative View
Have you seen the press recently? Or passed through an airport and seen the massive billboards advertising IT companies? I have - and I've learnt something from them: Engineered Systems are the best thing ever. I also know this because I read it on the Oracle website... and on the IBM website, although IBM likes … Continue reading Engineered Systems – An Alternative View
Database Workload Theory
In the scientific world, theoretical physicists postulate theories and ideas, for example the Higgs Boson. After this, experimental physicists design and implement experiments, such as the Large Hadron Collider, to prove or disprove these theories. In this post I'm going to try and do the same thing with databases, except on a smaller budget, with less … Continue reading Database Workload Theory
Auto DOP with High Performance Storage
Guest Post Nate Fuzi is my friend and collegue, based out in the US fulfilling the same role that I perform in EMEA. He is also the person with which I have drunk more sake jello shots than I ever thought probable / sensible / acceptable. Nate recently wrote this note regarding the use of … Continue reading Auto DOP with High Performance Storage
The Ultimate Guide To Oracle Support
In an effort to provide useful content rather than just blathering on about stuff I've written an article on how to work with and understand Oracle Support. The idea is that if you know the way the organisation works, you can get the best out of your experiences with them. Nothing in the article is … Continue reading The Ultimate Guide To Oracle Support
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