Re: [subxacts] Fixing TODO items

Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
> There are some likely controversial changes; the Xid caches, in the
> first place.

No kidding ;-)

Do you have any theoretical or practical evidence for the usefulness of
the negxids cache?  Seems to me the shared memory space would be better
spent on allowing deeper nesting of the running-subxids list.  Also,
what happened to marking whether the running-subxids list has
overflowed?  If none of them have then there's no need to wonder whether
we have a still-running subxact.

The apparent lack of any locking on these data structures seems wrong
too.

            regards, tom lane