Hi,
I'm wondering which type of SSDs would be better for use with PostgreSQL.
Background:
At the moment, SSD drives fall into two categories..
Those that use internal-compression on the SandForce controller, which
gives very fast speeds for compressible data; and those that don't.
In benchmarks, the compressing style of drive do extremely well at
random writes as long as there's semi-compressible-data involved. They
still do well if uncompressible data is used, just usually not quite as
well as the competitors.
When it comes to reading data, there's no real difference.
So I just wondered how this might apply to PostgreSQL's workload?
I think the on-disk data is going to consist of a lot of random reads
and writes, with what I suspect is data that *does* compress quite well.
(At least on my data sets, that is. If I use gzip or lzma on the
postgres data directly, it gets MUCH smaller)
So on the face of it, I think the Sandforce-based drives are probably a
winner here, so I should look at the Intel 520s for evaluation, and
whatever the enterprise equivalent are for production.
I wondered if anyone else wiser than I has thought about this yet
though.. are there any downsides to that combination?
cheers,
Toby