Would it make sense to show the FSM stats for individual table vaccums as well? I'm wondering if the reason they aren't shown is because it wouldn't be useful or isn't practical, or just that it hasn't been done.

Brian

----- Original Message ----
From: Tom Lane <tgl@sss.pgh.pa.us>

If you're talking about the FSM statistics display, that only gets
printed by a database-wide VACUUM (one that doesn't name a specific
table).

regards, tom lane




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TIP 5: don't forget to increase your free space map settings

Brian Herlihy <btherl@yahoo.com.au> writes:
> Would it make sense to show the FSM stats for individual table vaccums as w=
> ell? I'm wondering if the reason they aren't shown is because it wouldn't =
> be useful or isn't practical, or just that it hasn't been done.

It was intentionally omitted in the original design, on the grounds that
after a single-table VACUUM there's no very good reason to think that
the global FSM stats are sufficiently complete to be accurate. Of
course, in a multi-database installation the same charge could be
leveled against the situation after a single-database VACUUM, so maybe
there's not a lot of strength in the argument.

IIRC the code change would be trivial, it's just a matter of judgment
whether the extra output is useful/trustworthy.

regards, tom lane

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TIP 9: In versions below 8.0, the planner will ignore your desire to
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On Tue, 16 Oct 2007 17:03:39 -0700 (PDT)
Brian Herlihy <btherl@yahoo.com.au> wrote:

> Would it make sense to show the FSM stats for individual table
> vaccums as well? I'm wondering if the reason they aren't shown is
> because it wouldn't be useful or isn't practical, or just that it
> hasn't been done.

I am not sure how useful it would be as the FSM is global. However what
would be useful is something like VACUUM SUMMARY, where I could get
"just" the stats instead of all the other output that comes along with
VERBOSE.

Joshua D. Drake

>
> Brian
>
> ----- Original Message ----
> From: Tom Lane <tgl@sss.pgh.pa.us>
>
> If you're talking about the FSM statistics display, that only gets
> printed by a database-wide VACUUM (one that doesn't name a specific
> table).
>
> regards, tom lane
>
>
>
>
> ---------------------------(end of
> broadcast)--------------------------- TIP 5: don't forget to increase
> your free space map settings
>


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Joshua D. Drake wrote:
> On Tue, 16 Oct 2007 17:03:39 -0700 (PDT)
> Brian Herlihy <btherl@yahoo.com.au> wrote:
>
> > Would it make sense to show the FSM stats for individual table
> > vaccums as well? I'm wondering if the reason they aren't shown is
> > because it wouldn't be useful or isn't practical, or just that it
> > hasn't been done.
>
> I am not sure how useful it would be as the FSM is global. However what
> would be useful is something like VACUUM SUMMARY, where I could get
> "just" the stats instead of all the other output that comes along with
> VERBOSE.

What would be really useful is to remove all that noise from vacuum and
make it appear on a view. 8.4 material all of this, of course.

--
Alvaro Herrera http://www.amazon.com/gp/registry/CTMLCN8V17R4
"Estoy de acuerdo contigo en que la verdad absoluta no existe...
El problema es que la mentira sí existe y tu estás mintiendo" (G. Lama)

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Alvaro Herrera <alvherre@commandprompt.com> writes:
> What would be really useful is to remove all that noise from vacuum and
> make it appear on a view.

Well, if you want something decoupled from VACUUM there's already
contrib/pg_freespacemap.

> 8.4 material all of this, of course.

I am hoping that we rewrite FSM into the distributed DSM structure
that's been talked about, so that the whole problem goes away in 8.4.

regards, tom lane

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TIP 9: In versions below 8.0, the planner will ignore your desire to
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