Re: Loss of data and info from system tables!!

Tom Lane wrote:

Noel Faux <noel.faux@med.monash.edu.au> writes: 

We generally only vacuum 
tables which are affected by deletes, inserts and updates.   

You can't do that as an exclusive practice :-(.  In particular I suppose
that you never vacuumed your system catalogs at all, and now you are
behind the eight ball because transaction IDs wrapped around.  See
http://www.postgresql.org/docs/7.4/static/maintenance.html#VACUUM-FOR-WRAPAROUND 

Thanks heaps for the info.  So from reading the following post http://archives.postgresql.org/pgsql-hackers/2005-02/msg00407.php
the only way to retrieve the data is by 'could use pg_resetxlog to back up the NextXID counter enough to
make your tables and databases reappear (and thereby lose the effects of
however many recent transactions you back up over).

Once you've found a NextXID setting you like, I'd suggest an immediate
pg_dumpall/initdb/reload to make sure you have a consistent set of data.
Don't VACUUM, or indeed modify the DB at all, until you have gotten a
satisfactory dump.'

How much of the data am I likely to get back??
Is there any other way to recovery the data??

Many thanks
Noel

		regards, tom lane

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TIP 9: the planner will ignore your desire to choose an index scan if your     joining column's datatypes do not match 

-- 
PhD student
Department of Biochemistry and Molecular Biology
Monash University
Clayton 
Victoria 3800
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Ph: +61 3 9905 1418
e-mail: noel.faux@med.monash.edu.au
web site: http;//vbc.med.monash.edu.au/~fauxn/