On Wed, Jun 4, 2014 at 5:10 PM, Andres Freund <and...@2ndquadrant.com> wrote:
> Looks like you're hitting the issue described in > > http://archives.postgresql.org/message-id/20140530121631.GE25431%40alap3.anarazel.de Aha, so the problem looks like this: - all multixact contents was purged (9.2 to 9.3 incompatibility) - the only offset was the 0000 file created by initidb during bootstrap - truncation code in vacuum assumed the page related to multixact it tried to truncate actually exists - the assumption was based on the fact that there exists a page earlier than the one it tried to truncate - due to the wrong assumption, there was an attempt to truncate a non-existing page, resulting in the error. Now that makes sense, thank you very much. Vacuum runs w/o issues once I removed that 0000 file. I think it should be safe to recommend removing the 0000 file for everyone with the same problem. The 2 cases where 0000 file is actually used are: - when the are no more then 2 pages of offsets (0000 and 0001) since the server creation - when the multixacts wrapped around and 0000 is not the first page. I think in both cases there will be no gaps in segments in offsets, so the problem won't be there in the first place. Cheers, -- Alexey Klyukin
