The Real Cost of Oracle RAC

Pile of gold and silver coins representing the escalating license cost of Oracle RAC

Oracle RAC is sold as a high-availability solution, but its real cost – in licenses, complexity and the hidden assumption that losing a node doesn’t count as an outage – is rarely made explicit.

The Real Cost of Enterprise Database Software

Fanned stack of US dollar bills representing the high cost of enterprise database software licensing

Oracle database licensing is eye-wateringly expensive per CPU core – and storage costs, often seen as prohibitive, represent a surprisingly small fraction of the total three-year spend.

Storage Myths: Put Oracle Redo on SSD

Close-up of a tortoise, symbolising the slow write performance of SSDs for Oracle redo logs

Putting Oracle redo logs on SSD is a common reflex response to slow databases – but it usually misdiagnoses the problem, and SSDs handle write-heavy sequential workloads worse than you might expect.

Storage Myths: IOPS Matter

Person shouting the word IOPS, illustrating the storage industry's obsession with the metric

IOPS figures dominate flash storage marketing, but for databases latency is the metric that matters – high IOPS at unpredictable latency deliver no real-world value.

SLOB2: Testing The Effect Of Oracle Blocksize

I recently posted a test harness for generating physical I/O using the new version of SLOB (the Silly Little Oracle Benchmark) known as SLOBv2. This test harness can be used for driving varying workloads and then processing the results for use in ... well, wherever really. Some friends of mine are getting very adept with … Continue reading SLOB2: Testing The Effect Of Oracle Blocksize →

The Most Important Thing You Need To Know About Flash

NAND flash memory chip on a circuit board – the consumer-driven technology at the heart of enterprise storage

NAND flash development is driven by the consumer market – not the enterprise. The question to ask any flash vendor isn't "how fast?" but "where's your innovation?"

Does My Database Need Flash?

A parody of the Cillit Bang ad slogan reading "Flash and the disk is gone", the featured image for the Storage for DBAs post on flash storage

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

Plates of sushi on a kaiten conveyor belt, used as an analogy for the rotational latency and seek time of spinning disk storage

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.

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 →

Flash Enables Human-Time Analytics

Analytics. Apparently it's "the discovery and communication of meaningful patterns in data". Allegedly it's the "Next Holy Grail". By definition it's "the science of logical analysis". But what is it really? We know that it is considered a type of Business Intelligence. We know that when applied to massive volumes of information it is often described … Continue reading Flash Enables Human-Time Analytics →