Re: [HACKERS] Overhead for stats_command_string et al, take 2

Bruce Momjian <bruce@momjian.us> writes:
> Tom Lane wrote:
>> This is an ugly patch.  Why not *one* test of the GUC variable, inside
>> set_ps_display(), and no side-effects on callers?  You would need to
>> force an initial update from init_ps_display, but that only requires a
>> small amount of code refactoring inside ps_status.c.

> Consider all the helper processes that set their process title.  The
> only thing I can think of is to add a boolean to set_ps_display() so say
> whether this is per-command set or not. Is that your idea?

No, that's not what I said at all.  Currently init_ps_display doesn't
actually force the display to update; it's left to the first
set_ps_display call to do that.  If we made init_ps_display update the
status unconditionally, then set_ps_display could be a conditional
no-op, and in the helper process setup code

    /* Identify myself via ps */
    init_ps_display("autovacuum process", "", "");
    set_ps_display("");

we could remove the now-unnecessary set_ps_display("") calls, but
the other set_ps_display() calls would stay exactly like they are.

            regards, tom lane