Database Reference
In-Depth Information
EFDs and SSDs are dollars per GB but cents per IOP, whereas spinning disks
are cents per GB and dollars per IOP. In order to achieve the best balance, you
need some of each. This is why many types of storage array include automatic
storage tiering. Automatic storage tiering is most effective when done at the block
level because individual blocks can be moved between the EFD and spinning
disk storage as performance and capacity needs change. Where available, we
recommend you use automatic storage tiering and seek advice from your storage
vendor to ensure effective implementation and operations.
To make calculating performance and capacity based on different types of disk,
numbers of disks, and RAID types easy, see the calculator at
Note
There are many new types of enterprise storage systems and converged
architectures on the market today that have moved away from using RAID
as the main means of data protection and instead have their own methods.
Often these alternative methods can achieve the same reliability and data
protection levels as RAID, but without all of the complication and
performance penalties. If you are using a system that doesn't rely on RAID
for data protection, you can safely ignore this section. You should seek
advice from your vendor with regard to sizing for capacity and
performance based on their data protection methods and overheads.
SQL Performance with Server-Side Flash Acceleration
There is one storage technology that is currently sweeping the IT industry and
revolutionizing performance, and that is NAND flash, in the form of SSDs, EFDs, and
PCIe devices. When it comes to SQL performance, we think the lyrics of the Queen song
“Flash Gordon” are very appropriate (see
Figure 6.38
). I wonder if they could see the
future of enterprise and web-scale data centers when they wrote that song? Either way,
as the previous section illustrated with the discussion around SSD and EFD in your
storage array (including All Flash Arrays), it liberates performance for SQL from the
tyranny of slow spinning disks that may no longer be economic.
Figure 6.38
Flash acceleration and lyrics from the classic Queen song “Flash Gordon.”
But flash in an array has some limitations, and there is another location where we can
