On Mon, Nov 15, 2010 at 11:37 AM, Thom Brown <thom@linux.com> wrote:
> Is this somewhere OpenCL is an option?
>
Sure.
Personally I wonder whether the context switching is fast enough to
handle a multi-user system. In the past graphics cards have always
been targeted at the idea of a single-user workstation playing games
where the game wants to talk directly to the graphics card. But
increasingly that's not true, with things like opengl based window
managers and so on. Perhaps things have changed enough that it would
be conceivable to have dozens of separate processes all downloading
snippets of code and time-sharing the GPU now.
The other problem is that Postgres is really not architected in a way
to make this easy. Since our data types are all flexible pluggable
sets of functions it's unclear whether any of them match the data
types that GPUs know about. The obvious algorithm to toss to the GPU
would be sorting -- but that would only work for floats and even then
it's not clear to me that the float semantics on the GPU necessarily
match those of the host processor.
I've seen papers on doing relational joins using GPUs and I'm sure
there are other algorithms we wonderful stuff we could do. But if it
comes at the cost of being able to handle arbitrary join clauses it'll
be a tough sacrifice to make.
--
greg