Bruce Momjian <pgman@candle.pha.pa.us> writes:
>> Will a HUP cause the child postgres processes to restart as well?
>> What if a transaction is occuring at the time of the HUP?
> Again, no effect on children of postmaster.
Not so. The postmaster responds to the signal as soon as it's idle,
rereads the conf file itself, and rebroadcasts SIGHUP to all its
children. The children then reread the conf file immediately after they
next receive a query from their clients. See postmaster/postmaster.c
and tcop/postgres.c.
A lot of the configuration file entries are not allowed to change in a
running backend, so the children will ignore attempted changes in those
entries. But for entries that can be changed on the fly, the response
is reasonably prompt across the board.
regards, tom lane