On Wed, 4 Sept 2024 at 03:06, Robert Haas <robertmh...@gmail.com> wrote: > > On Mon, Sep 2, 2024 at 1:46 PM Tomas Vondra <to...@vondra.me> wrote: > > But say we add a GUC and set it to -1 by default, in which case it just > > inherits the max_locks_per_transaction value. And then also provide some > > basic metric about this fast-path cache, so that people can tune this? > > All things being equal, I would prefer not to add another GUC for > this, but we might need it.
I think driving the array size from max_locks_per_transaction is a good idea (rounded up to the next multiple of 16?). If someone comes along one day and shows us a compelling case where some backend needs more than its fair share of locks and performance is bad because of that, then maybe we can consider adding a GUC then. Certainly, it's much easier to add a GUC later if someone convinces us that it's a good idea than it is to add it now and try to take it away in the future if we realise it's not useful enough to keep. David
