Re: [PATCH] Unremovable tuple monitoring

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Yeb Havinga <yebhavinga@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@commandprompt.com>, Royce Ausburn <royce.ml@inomial.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Kevin Grittner <kevin.grittner@wicourts.gov>
Date: 2011-11-16T14:58:43Z
Lists: pgsql-hackers
Yeb Havinga <yebhavinga@gmail.com> writes:
> On 2011-11-16 15:34, Tom Lane wrote:
>> The dividing line is enormously unstable though.  pgstattuple's idea of
>> RecentGlobalXmin could even be significantly different from that of a
>> concurrently running VACUUM.  I can see the point of having VACUUM log
>> what it did, but opinions from the peanut gallery aren't worth much.

> I don't understand your the last remark so I want to get it clear: I 
> looked up peanut gallery on the wiki. Is 'opinion from the peanut 
> gallery' meant to describe my comments as patch reviewer? I'd appreciate 
> brutal honesty on this point.

No no no, sorry if you read that as a personal attack.  I was trying to
point out that a process running pgstattuple does not have a value of
RecentGlobalXmin that should be considered authoritative --- it is only
a bystander, not the process that might do actual cleanup work.

			regards, tom lane