From: Tom Lane <tgl@sss.pgh.pa.us>
To: tyagel@yahoo.com
Cc: pgsql-general@postgresql.org
Subject: Re: Vacuum related question
Date: Sat, 18 Sep 2004 12:06:24 -0400
Message-ID: <4715.1095523584@sss.pgh.pa.us> (raw)
In-Reply-To: <EOEFLPAIAEDLPGGLIIGNEEEACIAA.tyagel@yahoo.com>
References: <EOEFLPAIAEDLPGGLIIGNEEEACIAA.tyagel@yahoo.com>
"G. Thomas Yagel, Jr." <tyagel@yahoo.com> writes:
> After 12 hours I stopped inserting recods and started a "vacuum verbose".
> The vacuuming has taken almost 2 hours now and is not even finished. What I
> don't understand is why there is so much vacuuming to be done on some tables
> that are only being inserted into. As an example, I have pasted the output
> from the vacuuming of the pg_largeobject table.
You may think you've only inserted, but this output says differently:
> INFO: "pg_largeobject": found 18317486 removable, 21326336 nonremovable row
> versions in 2119638 pages
Those 18 million dead rows didn't appear out of nowhere; they could only
have come from deleting or updating large objects (BLOBs).
The reason for the multiple index-cleaning cycles is that vacuum_mem was
only high enough to remember about 1.4 million dead rows at a time.
You could have sped up the process by setting vacuum_mem higher.
regards, tom lane
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To: pgsql-general@postgresql.org
Cc: tgl@sss.pgh.pa.us, tyagel@yahoo.com
Subject: Re: Vacuum related question
In-Reply-To: <4715.1095523584@sss.pgh.pa.us>
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