vacuumlo fails pgsql ver 8.3
Gday all,
I have a large database with many large objects, linked to a single table.
I have been trying to backup the database so I can migrate to a later
version, but the backup has been failing due to problems within
pg_largeobject. I am not surprised at these errors, because the server
is not protected by UPS and has had several power outages (I'm working
on this with the database owner!) over the past few years.
Recently I tried to perform a vacuumlo, as I thought this might clear up
the problems, and the process fails after a long time with the following
log:
F:\PostgreSQL\8.3\bin>vacuumlo -U xxx -W xxx
Password:
Failed to remove lo 317198793: ERROR: large object 317198793 does not exist
Failed to remove lo 4065905288: ERROR: current transaction is aborted,
commands
ignored until end of transaction block
Failed to remove lo 0: ERROR: current transaction is aborted, commands
ignored
until end of transaction block
F:\PostgreSQL\8.3\bin>
When I added the -v option, there were many "removing lo xxxxx" messages
before the above messages appeared. I have previously tried to reindex
pg_largeobject, but that process failed as well.
Can someone offer please offer some advice on how to resolve this?
TIA.
Pat Heuvel
(in Australia)
Pat Heuvel <pheuvel@tpg.com.au> writes:
[ vacuumlo fails ]
When I added the -v option, there were many "removing lo xxxxx" messages
before the above messages appeared. I have previously tried to reindex
pg_largeobject, but that process failed as well.
You need to get the index consistent before trying vacuumlo; that
program is not designed to deal with inconsistent catalogs.
What exactly happens when you try to reindex pg_largeobject?
regards, tom lane
On 6/02/2012 4:39 AM, Tom Lane wrote:
Pat Heuvel<pheuvel@tpg.com.au> writes:
[ vacuumlo fails ]
When I added the -v option, there were many "removing lo xxxxx" messages
before the above messages appeared. I have previously tried to reindex
pg_largeobject, but that process failed as well.You need to get the index consistent before trying vacuumlo; that
program is not designed to deal with inconsistent catalogs.What exactly happens when you try to reindex pg_largeobject?
regards, tom lane
ERROR: could not create unique index "pg_largeobject_loid_pn_index"
DETAIL: Table contains duplicated values.
********** Error **********
ERROR: could not create unique index "pg_largeobject_loid_pn_index"
SQL state: 23505
Detail: Table contains duplicated values.
Pat Heuvel <pheuvel@tpg.com.au> writes:
On 6/02/2012 4:39 AM, Tom Lane wrote:
What exactly happens when you try to reindex pg_largeobject?
ERROR: could not create unique index "pg_largeobject_loid_pn_index"
DETAIL: Table contains duplicated values.
Could be worse. What you'll need to do is look through the
pg_largeobject catalog for duplicated (loid, pageno) values, and
manually DELETE the redundant rows, or else reassign them new OIDs
if you want to keep the data.
A tip for issuing the removal commands is to use the CTID column to
distinguish otherwise-identical rows, ie you could do something
like
select ctid, loid, pageno from pg_largeobject
where (loid, pageno) in (select loid, pageno from pg_largeobject
group by 1, 2 having count(*) > 1);
... examine results ...
delete from pg_largeobject where ctid = '...';
I believe you'll need to do any direct DELETE or UPDATE on the
catalog as superuser.
regards, tom lane
On 7/02/2012 3:48 AM, Tom Lane wrote:
Pat Heuvel<pheuvel@tpg.com.au> writes:
On 6/02/2012 4:39 AM, Tom Lane wrote:
What exactly happens when you try to reindex pg_largeobject?
ERROR: could not create unique index "pg_largeobject_loid_pn_index"
DETAIL: Table contains duplicated values.Could be worse. What you'll need to do is look through the
pg_largeobject catalog for duplicated (loid, pageno) values, and
manually DELETE the redundant rows, or else reassign them new OIDs
if you want to keep the data.A tip for issuing the removal commands is to use the CTID column to
distinguish otherwise-identical rows, ie you could do something
like
select ctid, loid, pageno from pg_largeobject
where (loid, pageno) in (select loid, pageno from pg_largeobject
group by 1, 2 having count(*)> 1);
... examine results ...
delete from pg_largeobject where ctid = '...';I believe you'll need to do any direct DELETE or UPDATE on the
catalog as superuser.regards, tom lane
Thanks Tom, I'll give that a try.