Database Storage Performance Testing in a Hurry
Sep 22, 2009, 00:02 (0 Talkback[s])
(Other stories by Jeremy Zawodny)
"Having little time and lots to do, I decided that I was mainly
interested in the “painful” cases we see. For example,
it’s interesting to note that the Fusion-io card has the
advantage of being plugged into a PCI express slot and is not
subject to the limitations of more traditional disk I/O channels.
That means you can move a lot of data VERY quickly. But
that’s not a concern in most of our cases.
"The servers generally have a fair amount of RAM (32GB is
common) and most of that is used for InnoDB’s buffer pool.
What does hurt are queries that cause InnoDB to hit the disks to
fetch pages that haven’t been cached. These are generally
small random reads that are scattered all over the disk. As
I’ve discussed in previous articles, this is a latency (seek
time) issue, not a throughput issue.
"But the Fusion-io card is SLC memory based, so the
“seek” times should be VERY small. The same is true for
the regular SSD."