Robert Haas <robertmh...@gmail.com> writes: > On Thu, Nov 28, 2013 at 1:46 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> We could add an extra test in FastPathGrantRelationLock's loop to make >> it remember the first unused slot rather than the last one, but that >> would add some cycles there, partially negating any benefit. Instead >> I propose that we reverse the direction of the search loop, as attached.
> Well, the reason why the array is only 64 bytes in size is to make > sure that searching the whole thing is really fast. We figure we're > going to have to do that often, so it needs to be cheap. If it's not, > we're hosed already, I think. I actually suspect the bitmask manipulations cost more than the touches of fpRelId[]. I agree that there's no reason to think that this area needs really tense micro-optimization, but if we can get some savings for zero added cost/complexity, why not? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers