[Please note that a more up-to-date post on this subject can be found here] In my previous post on the subject of the new ASM Filter Driver (AFD) feature introduced in Oracle's 12.1.0.2 patchset, I installed the AFD to see how it fulfilled its promise that it "filters out all non-Oracle I/Os which could cause accidental overwrites". … Continue reading Oracle 12.1.0.2 ASM Filter Driver: Advanced Format Fail
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Oracle 12.1.0.2 ASM Filter Driver: First Impressions
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
New AWR Report Format: Oracle 11.2.0.4 and 12c
This is a post about Oracle Automatic Workload Repository (AWR) Reports. If you are an Oracle professional you doubtless know what these are - and if you have to perform any sort of performance tuning as part of your day job it's likely you spend a lot of time immersed in them. Goodness knows I … Continue reading New AWR Report Format: Oracle 11.2.0.4 and 12c
New section: Oracle SLOB Testing
For some time now I have preferred Oracle SLOB as my tool for generating I/O workloads using Oracle databases. I've previously blogged some information on how to use SLOB for PIO testing, as well as shared some scripts for running tests and extracting results. I've now added a whole new landing page for SLOB and … Continue reading New section: Oracle SLOB Testing
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.
Oracle SLOB On Solaris
Guest Post This is another guest post from my buddy Nate Fuzi, who performs the same role as me for Violin but is based in the US instead of EMEA. Nate believes that all English people live in the Dickensian London of the 19th century and speak in Cockney rhyming slang. I hate to disappoint, … Continue reading Oracle SLOB On Solaris
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