On 2017-04-24 14:43:11 -0400, Tom Lane wrote:
> (We have accepted that kind of overhead for DSM segments, but the
> intention I think is to allow only very trivial data structures in
> the DSM segments. Losing compiler pointer type checking for data
> structures like the lock or PGPROC tables would be horrid.)
The relptr.h infrastructure brings some of the type-checking back, but
it's still pretty painful. And just as important, it's quite noticeable
performance-wise. So we have to do it for dynamic shm (until/unless we
go to using threads), but that doesn't mean we should do it for some of
the most performance critical data structures in PG...
- Andres