Re: Vacuum questions...

[Hannu Krosing <hannu(at)skype(dot)net>]

On L, 2005-09-24 at 20:25 -0700, Joshua D. Drake wrote:

> Actually this also probably would not gain you much in 8.1
> as vacuum in theory is already dealing with itself.

Interesting. Could you explain it in a more detailed way ?
How does vacuum "deal with itself" in 8.1 ?

> >Also, would it be possible to add some means to check the status of a
> >running vacuum? Even with vacuum verbose, once it starts in on a large
> >table you have no way to know how far along it is.
> >  
> >
> That is an interesting thought... Perhaps a quick scan of
> the table to see how many dead rows there are? Then check
> back every n/10 ? Hmmm... I am not a C guy so I don't know if
> that is technically feasible (although probably possible) but it
> is interesting from a DBA perspective.

Not sure of a "quick scan" approach, espacially for tables big enough
for the progress info would be interesting (in my experience a scan is
never quick).

Perhaps VACUUM could send some statistics after each N pages and this
would then be available through something similar to pg_statistics
table.

-- 
Hannu Krosing <hannu(at)skype(dot)net>