Simon Riggs <si...@2ndquadrant.com> writes: > On Wed, May 25, 2011 at 1:44 PM, Robert Haas <robertmh...@gmail.com> wrote: >> On Wed, May 25, 2011 at 8:27 AM, Simon Riggs <si...@2ndquadrant.com> wrote: >>> Design seemed relatively easy from there: put local lock table in >>> shared memory for all procs. We then have a use_strong_lock at proc >>> and at transaction level. Anybody that wants a strong lock first sets >>> use_strong_lock at proc and transaction level, then copies all local >>> lock data into shared lock table,
>> I'm not following this... > Which bit aren't you following? It's a design outline for how to > implement, deliberately brief to allow a discussion of design > alternatives. What I'm not following is how moving the local lock table into shared memory can possibly be a good idea. The reason we invented the local lock table in the first place (we didn't use to have one) is so that a process could do some manipulations without touching shared memory. (Notably, it is currently nearly free, and certainly lock-free, to re-request a lock type you already hold. This is not an infrequent case.) That advantage will go away if you do this. 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