Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> I finally got around to look at this. Attached patch adds a
> HASH_FIXED_SIZE flag, which disables the allocation of new entries
> after the initial allocation. I believe we have consensus to make
> the predicate lock hash tables fixed-size, so that there's no
> competition of the slack shmem space between predicate lock
> structures and the regular lock maanager.
OK, I can see why you preferred this -- the existing exchange of
slack space with the HW lock tables remains unchanged this way, and
only the new tables for predicate locking have the stricter limits.
This makes it very unlikely to break current apps which might be
unknowingly relying on existing allocation behavior in the HW
locking area. Smart.
I hadn't picked up on your intent that the new flag would only be
used for the new tables, which is why it wasn't quite making sense
to me before.
Thanks!
-Kevin