On Sun, Aug 1, 2021 at 11:41 PM Amit Khandekar <amitdkhan...@gmail.com> wrote: > > > FWIW, I anticipate some push back from the community because of the fact that the optimization relies on statistical phenomena. > > I dug into this issue for tsvector type. Found out that it's the way > in which the sign array elements are arranged that is causing the pointers to > be misaligned: [...] > If siglen is not a multiple of 8 (say 700), cache[j].sign will in some > cases point to non-8-byte-aligned addresses, as you can see in the > above code snippet. > > Replacing siglen by MAXALIGN64(siglen) in the above snippet gets rid > of the misalignment. This change applied over the 0001-v3 patch gives > additional ~15% benefit. MAXALIGN64(siglen) will cause a bit more > space, but for not-so-small siglens, this looks worth doing. Haven't > yet checked into types other than tsvector.
Sounds good. > Will get back with your other review comments. I thought, meanwhile, I > can post the above update first. Thinking some more, my discomfort with inline functions that call a global function doesn't make logical sense, so feel free to do it that way if you like. -- John Naylor EDB: http://www.enterprisedb.com
