Oracle AWR reports contain multiple I/O sections that measure subtly different things – here's what each one actually captures and why conflating them leads to the wrong conclusions.
Oracle AWR Reports: Understanding I/O Statistics
Category: Storage
Storage is the foundation on which database performance is built. Latency, throughput, and consistency at this layer directly shape how systems behave under load.
While often abstracted away in modern architectures, storage characteristics continue to define the limits of what databases can achieve – especially as workloads become more demanding and less predictable.
New script for setting up multipath.conf entries
A shell script that automates the creation of Linux multipath.conf entries for storage devices – originally written for Violin arrays but applicable to other storage with minimal changes.
Oracle Fixes The 4k SPFILE Problem…But It’s Still Broken
Oracle patched the SPFILE failure on 4k devices in 11.2.0.4 – but the underlying support for Advanced Format storage remains incomplete and unreliable.
Playing The Data Reduction Lottery
Flash vendors routinely quote “effective capacity” figures based on optimistic data reduction assumptions – understanding what those numbers really mean is essential before signing a purchase order.
Oracle Exadata X4 (Part 2): The All Flash Database Machine?
With the X4's flash capacity changes examined, this post asks the harder question: is Oracle quietly turning Exadata into an all-flash array – and what would that mean for pricing?
Predictions for 2014: DataBase-as-a-Service
It's that time of year again where lots of people write articles which begin with the words "It's that time of year again..." and make endless references to crystal balls, tea leaves and the benefits of hindsight. But not me, I'm not descending into cliché. Apart from that first sentence, which with the benefit of … Continue reading Predictions for 2014: DataBase-as-a-Service
Oracle Exadata X4 (Part 1): Bigger Than It Looks?
The Exadata X4 announcement looked like a routine spec bump – but a closer reading of Oracle's positioning reveals something more significant about where the product is heading.
Storage Myths: Storage Compression Has No Downside
Storage-level compression trades capacity for CPU cycles and read latency – understanding that trade-off matters more than the headline reduction ratios vendors put in their datasheets.
Storage Myths: Dedupe for Databases
Data deduplication promises capacity savings, but databases are one of the worst use cases for it – the technology’s assumptions break down against the entropy and I/O patterns of database workloads.
Understanding Disk: Over-Provisioning
When performance capacity drives storage decisions, waste is the inevitable result – stranded terabytes, short-stroking, and a growing gap between what disk holds and what it can actually deliver.
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