Feeds

In the spin of SSDs on database servers

The future is static

Maximizing your infrastructure through virtualization

SSDs can be thought of as a hybrid between rotating media and volatile memory and their adoption should significantly change intelligent indexing behavior. At its broadest this simply means that good DBAs will use fewer indexes. Also, the use of SSDs will almost certainly affect decisions about the placement of indexes: for example there may be far less of a performance hit from keeping data and indexes on the same device because SSDs are essentially random access.

Ingres and Postgres creator Michael Stonebraker is well known for his controversial opinion of MapReduce and he has also voiced strong views on row- and column-oriented databases. In transactional systems we tend to read most of the data in a row and in analytical systems we tend to read most of the contents of a column - somewhat of a simplification, but essentially true.

Stonebraker's argument is that in analytical databases we should store the data column-by-column so that the data most likely to be read together is stored together. It's a perfectly reasonable argument when discussing an HDD and - whilst I'm not suggesting that the argument evaporates completely with random access storage - I am saying that the use of SSDs will materially alter the balance here. In other words, for many systems it simply may not matter whether we use column or row-oriented storage.

Clearly SSDs are going to be seen in wider deployment on general purpose servers. And, just as we’ve developed ways of extracting the best from rotating media, we must now engage upon doing the same for solid state drives.

Then once we've grasped the idea that storage need not rotate, alternatives to SSDs also enter the picture. Why not oscillate instead? DataSlide, for example, is developing a Hard Rectangular Drive (HRD) with a "massively parallel 2D array of magnetic heads" past which the media moves. All sorts of good vibrations surround this device.

Bootnote: SSD explained

An SSD is a block of memory acting as a storage medium (meaning, incidentally, that the D in SSD is a misnomer as there's nothing physically disk-like about an SSD). The latest models, like Intel's X25-M, use NAND flash memory technology, which doesn't use power to maintain stored data. NAND is short for 'Not AND', a Boolean logic operator that describes how data is stored: its use in SSDs was pioneered by Samsung.

There are two flavors of NAND flash: single-level cell (SLC) which stores one bit per cell and multi-level cell (MLC) that - you guessed it - stores two. Both can be read very rapidly but writing to SLC is around twice as fast as writing to MLC.

On the other hand, MLC technology is cheaper: the 80Gb X25-M is MLC and the new bulk purchase price - 1,000 units - is $225, which works out at under $3 per gigabyte. One SLC Intel 32Gb X25-E costs around $350 or $11-ish per gig which, whilst not directly comparable for several reasons, at least gives a feel for the price differential. ®

The Power of One eBook: Top reasons to choose HP BladeSystem

More from The Register

next story
Sysadmin Day 2014: Quick, there's still time to get the beers in
He walked over the broken glass, killed the thugs... and er... reconnected the cables*
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
SHOCK and AWS: The fall of Amazon's deflationary cloud
Just as Jeff Bezos did to books and CDs, Amazon's rivals are now doing to it
BlackBerry: Toss the server, mate... BES is in the CLOUD now
BlackBerry Enterprise Services takes aim at SMEs - but there's a catch
The triumph of VVOL: Everyone's jumping into bed with VMware
'Bandwagon'? Yes, we're on it and so what, say big dogs
Carbon tax repeal won't see data centre operators cut prices
Rackspace says electricity isn't a major cost, Equinix promises 'no levy'
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.