On Fri, 17 Oct 2014 13:12:27 -0400 Tom Lane <t...@sss.pgh.pa.us> wrote:
> CK Tan <ck...@vitessedata.com> writes: > > The bigint sum,avg,count case in the example you tried has some > > optimization. We use int128 to accumulate the bigint instead of numeric in > > pg. Hence the big speed up. Try the same query on int4 for the improvement > > where both pg and vitessedb are using int4 in the execution. > > Well, that's pretty much cheating: it's too hard to disentangle what's > coming from JIT vs what's coming from using a different accumulator > datatype. If we wanted to depend on having int128 available we could > get that speedup with a couple hours' work. > > But what exactly are you "compiling" here? I trust not the actual data > accesses; that seems far too complicated to try to inline. > > regards, tom lane > > I don't have any inside knowledge, but from the presentation given at the recent SFPUG followed by a bit of google-fu I think these papers are relevant: http://www.vldb.org/pvldb/vol4/p539-neumann.pdf http://sites.computer.org/debull/A14mar/p3.pdf -dg -- David Gould 510 282 0869 da...@sonic.net If simplicity worked, the world would be overrun with insects. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
