On 2018-Dec-28, Tom Lane wrote: > I wrote: > > Alvaro Herrera <alvhe...@2ndquadrant.com> writes: > >> I looked at > >> https://github.com/postgrespro/pg_wait_sampling/blob/master/pg_wait_sampling.c > >> https://github.com/citusdata/citus/search?q=pgproc&unscoped_q=pgproc > >> and skimmed a few others can't find any instance where the full struct > >> is used, as opposed to just a pointer to it. > > > No, the point Michael is making is that the array stride in the ProcArray > > is part of our ABI. For example, accessing a PGPROC from its pgprocno > > using the GetPGProcByNumber macro will be broken if we change the > > struct size. I do not think you can assume that no extension does that. > > In fact, there's a counterexample right here in pg_wait_sampling: > > https://github.com/postgrespro/pg_wait_sampling/blob/master/pg_wait_sampling.c#L343
Ughh. I stand corrected. This seems a terrible interface, from an ABI compatibility point of view, and exposing proclist_node_get() as an inline function, doubly so. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services