Is there a best practice for data files on flash? With random read/write, does
flash provide a performance increase over ssd or flash?
-----Original Message-----
From: timseanhall@xxxxxxxxx [mailto:timseanhall@xxxxxxxxx] On Behalf Of Tim Hall
Sent: Wednesday, December 16, 2015 10:41 AM
To: Andrew Kerber
Cc: Kellyn Pot'Vin-Gorman; ORACLE-L; Storey, Robert (DCSO)
Subject: Re: SSD usage
Hi.
The experience of Exadata Smart Flash Logging may prove useful in making a
decision. This feature allows Exadata to make two writes, one to flash and one
to disk. Whichever completes first wins. If you read some of the posts about
this feature, you will see a number of people saying that very few writes
complete first on flash. In Jason Arneil's post it was 2.7% of log writes went
to flash. In all other cases, disk beat flash. Results will vary depending on
the type of workload.
What does this mean in general terms, especially for non-Exadata people? Redo
on flash is not guaranteed to improve performance. In some workloads, it could
actually reduce performance.
As Kellyn mentioned in the quoted text above, you may get better bang for your
buck putting other things on flash like data files. As always, the answer is
"it depends". :) You need to make a change, test it, rinse and repeat. :)
Cheers
Tim...
��i��0���zX���+�� n��{�+i�^
