From: Jean-David Beyer <jeandavid8@verizon.net>
To: pgsql performance <pgsql-performance@postgresql.org>
Subject: Curious about dead rows.
Date: Sat, 10 Nov 2007 11:27:07 -0500
Message-ID: <4735DBDB.5050208@verizon.net> (raw)
I am doing lots of INSERTs on a table that starts out empty (I did a
TRUNCATE on it). I am not, AFAIK, doing DELETEs or UPDATEs. Autovacuum is
on. I moved logging up to debug2 level to see what was going on, and I get
things like this:
"vl_as": scanned 3000 of 5296 pages, containing 232944 live rows and 1033
dead rows; 3000 rows in sample, 411224 estimated total rows
A little later, it says:
"vl_as": scanned 3000 of 6916 pages, containing 233507 live rows and 493
dead rows; 3000 rows in sample, 538311 estimated total rows
(I suppose that means autovacuum is working.) Is this normal, or have I got
something wrong? Why so many dead rows when just doing inserts? It is not
that I think the number is too high, considering the number of rows in the
table at the point where I copied this line. It is just that I do not
understand why there are any.
I could easily understand it if I were doing UPDATEs.
postgresql-8.1.9-1.el5
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To: pgsql-performance@postgresql.org
Cc: jeandavid8@verizon.net
Subject: Re: Curious about dead rows.
In-Reply-To: <4735DBDB.5050208@verizon.net>
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