Re: A question about pages. Still not clear

From: Guido Barosio <gbarosio(at)gmail(dot)com>
To: tmorelli(at)tmorelli(dot)com(dot)br
Cc: pgsql-novice(at)postgresql(dot)org
Subject: Re: A question about pages. Still not clear
Date: 2006-01-12 15:07:04
Message-ID: f7f6b4c70601120707r25774f7fuf56b87267ccd5ee7@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-novice

quote: And, finally, what does it mean: "contrib/pgstattuple/ " (from your
last answer)

Means, check in the contrib/ directory in your pgsql source tree, for the
pgstattuple stuff.
It's extremely clear and may help you understanding some of your doubts.

Even more, you shall read the source of pgstattuple, and then call the
program. That will give you a big idea.

(tho,...check the contrib entirely, you will get a brand new snap of usefull
tools)

Best regards,
Guido.

On 1/12/06, tmorelli(at)tmorelli(dot)com(dot)br <tmorelli(at)tmorelli(dot)com(dot)br> wrote:
>
> Tom,
>
> I've done more tests. After re-creating a table with just one field
> (char(8000)), I inserted 26 records. Look at this:
>
> teste=# select relname, oid, relpages, reltuples from pg_class where oid
> >=
> 169982690;
> relname | oid | relpages | reltuples
> --------------------------+-----------+----------+-----------
> pg_toast_169982690_index | 169982694 | 1 | 0
> pg_toast_169982690 | 169982692 | 0 | 0
> ix | 169982695 | 2 | 26
> t | 169982690 | 1 | 26
> (4 rows)
>
> Every insert was like this:
>
> insert into t values (repeat('a',8000));
>
> Obviously, there must be some kind of compression (the toast table is
> empty!).
> The main question is:
>
> Is there any way of knowing exactly WHEN there will be a new page
> allocation?
> Is it configurable? How could I inspect compression stuff?
>
> VACUUM FULL VERBOSE did not make any difference.
>
> And, finally, what does it mean: "contrib/pgstattuple/ " (from your last
> answer)
>
> Best regards,
>
> Eduardo Morelli
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>

--
"Adopting the position that you are smarter than an automaticoptimization
algorithm is generally a good way to achieve lessperformance, not more" -
Tom Lane.

In response to

Browse pgsql-novice by date

  From Date Subject
Next Message Michael Fuhr 2006-01-12 16:59:33 Re: Removing duplicate entries
Previous Message A. Kretschmer 2006-01-12 14:25:33 Re: Forums