Re: Why frequently updated tables are an issue

Is there a TODO here? No one explained why frozen tuples are important.

---------------------------------------------------------------------------

Tom Lane wrote:
> Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
> > On 6/12/2004 3:45 PM, Tom Lane wrote:
> >> I don't think it would help very much to define a bit like that --- I
> >> can't believe that very many pages would contain only frozen tuples,
> >> unless you were to adopt an aggressive policy of using VACUUM FREEZE
> >> a lot.
>
> > I thought this implies an aggressive policy of freezing everything by
> > default. But I guess there is something I am not aware of that makes
> > aggressive freezing a bad thing.
>
> Well, it means extra I/O to freeze tuples that you otherwise probably
> never would. So it's not obvious that aggressive freezing in hopes of
> saving cycles later is a win.
>
> >> It might be interesting though to have some kind of "fast vacuum" mode
> >> that doesn't worry about freezing tuples, but only reclaiming dead ones.
>
> > Wouldn't that screw the current FSM population mechanisms? Not that my
> > suggestions above wouldn't do that either :-)
>
> Yeah, that's another "wholesale" mechanism that we'd have to look at
> refining.
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings
>

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073