Horton

Re: Some thoughts about i/o priorities and throttling vacuum

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@dcc.uchile.cl>
Cc: Shridhar Daithankar <shridhar_daithankar@persistent.co.in>, pgsql-hackers@postgresql.org
Date: 2003-10-17T15:59:50Z
Lists: pgsql-hackers 
Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
> The trick to keep in mind is that the XID comparison functions use
> "modulo" operations, _but_ there are special "frozen" XIDs that are
> always "committed" -- that's why a VACUUM FREEZE would relieve the table
> forever from this problem.

> (At least this is how I understand it -- I could be totally wrong here)

No, that's exactly correct.

			regards, tom lane