Hannu Krosing <hannu@tm.ee> writes:
> Is "PROC array slot number" something internal to postgres ?
Yes.
If we used PID then we'd eventually have 64K (or whatever the range of
PIDs is on your platform) different pg_temp_nnn entries cluttering
pg_namespace. But we only need MaxBackends different entries at any one
time. So the correct nnn value is 1..MaxBackends. BackendId meets the
need perfectly.
regards, tom lane