This is a very quick post, because I'm about to log off and take an extended summer holiday (or vacation as my crazy American friends call it... but then they call football "soccer" too). Before I go, I wanted to document my initial findings with the new ASM Filter Driver feature introduced in this week's … Continue reading Oracle 12.1.0.2 ASM Filter Driver: First Impressions
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.
Understanding Flash: SLC, MLC and TLC
SLC, MLC and TLC NAND flash differ in how many bits each cell stores. More bits per cell means lower cost and higher density – but slower performance and reduced endurance. This article explains the trade-offs for enterprise storage.
Understanding Flash: Blocks, Pages and Program / Erases
NAND flash memory stores data in pages but erases in blocks – a fundamental asymmetry that shapes everything from SSD performance to all-flash array design. This article explains the program/erase cycle and why it matters for database storage.
New My Oracle Support note on Advanced Format (4k) storage
In the past I have been a little critical of Oracle's support notes and documentation regarding the use of Advanced Format 4k storage devices. I must now take that back, as my new friends in Oracle ASM Development and Product Management very kindly offered to let me write a new support note, which they have … Continue reading New My Oracle Support note on Advanced Format (4k) storage
Understanding Flash: What Is NAND Flash?
NAND flash memory was invented in 1981 by Dr Fujio Masuoka at Toshiba. This article explains how flash works, why it differs from EPROM and EEPROM, and why program and erase operations behave differently.
Understanding Disk: Caching and Tiering
Caching and tiering promise to hide the performance cost of spinning disk – but both rely on predicting the unpredictable, and the slowest tier always waits.
The Ultimate Guide To Oracle with Advanced Format 4k
It's a brave thing, calling something the "Ultimate Guide To ..." as it can leave you open to criticism that it's anything but. However, this topic - of how Oracle runs on Advanced Format storage systems and which choices have which consequences - is one I've been learning for two years now, so this really … Continue reading The Ultimate Guide To Oracle with Advanced Format 4k
Postcards from Storageland: Two Years Flash By
The start of March means I have been working at Violin Memory for exactly two years. This also corresponds to exactly two years of the flashdba blog, so I thought I'd take stock and look at what's happened since I embarked on my journey into the world of storage. Quite a lot, as it happens... … Continue reading Postcards from Storageland: Two Years Flash By
More Problems with Oracle’s Support of 4k Devices
This is going to be another one of those posts, a bit like this one, that discuss the use of Oracle's database product with Advanced Format devices. I wish there weren't so many of these posts, but it seems that Oracle has a lot of issues with it's implementation of 4k support. (Before reading on, … Continue reading More Problems with Oracle’s Support of 4k Devices
Oracle ASMLib: Physical and Logical Blocksize
This article is about the use of Advanced Format devices on Oracle's ASMLib kernel library for Linux. For background, read this page on 4k sector sizes first, otherwise it might all sound like nonsense. Mind you, it mind sound like nonsense anyway, I can't guarantee anything here. By the way, a big hello to my … Continue reading Oracle ASMLib: Physical and Logical Blocksize
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