ERROR: could not open relation with OID

This morning we got the following error from a daily script that
produces a simple largest-table report:
ERROR: could not open relation with OID 597597503

From a bit of Googling, it seems that Postgres was unable to open the
physical file that contains the relation.

Is it possible that there was an error accessing the disk? How is the
filesystem that contains your PGDATA directory mounted?

Kind regards,
Andomar

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

On 04/22/2015 11:40 AM, Steve Crawford wrote:

This morning we got the following error from a daily script that
produces a simple largest-table report:
ERROR: could not open relation with OID 597597503

I reran the script and it completed without error.

Our server is running 9.1.15 from PgDg Ubuntu repos and the query run by
the script is:

SELECT
relname AS TABLE,
lpad ( pg_size_pretty ( pg_relation_size ( oid ) ), 9 ) AS SIZE,
( 100 * pg_relation_size ( oid ) /
( SELECT
sum ( pg_relation_size ( oid ) )
FROM
pg_class
WHERE
relkind = 'r' ) ) ::numeric ( 4, 1 ) AS percent
FROM
pg_class
WHERE
relkind = 'r'
ORDER BY
relpages DESC
LIMIT 60;

My research hasn't led to a definitive conclusion on how to trace this
issue and how much I should be concerned about this error.

If it is of importance, it appears that a temporary table and temporary
index were being created within the same second that the query was run.

Any advice?

WHERE
relkind = 'r'
AND
relpersistence != 't'

Cheers,
Steve

--
Adrian Klaver
adrian.klaver@aklaver.com

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

On 04/22/2015 01:25 PM, Adrian Klaver wrote:

If it is of importance, it appears that a temporary table and temporary
index were being created within the same second that the query was run.

Any advice?

WHERE
relkind = 'r'
AND
relpersistence != 't'

So to confirm. Fix the query and don't worry?

Cheers,
Steve

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

On 04/22/2015 02:37 PM, Steve Crawford wrote:

On 04/22/2015 01:25 PM, Adrian Klaver wrote:

If it is of importance, it appears that a temporary table and temporary
index were being created within the same second that the query was run.

Any advice?

WHERE
relkind = 'r'
AND
relpersistence != 't'

So to confirm. Fix the query and don't worry?

Well it is software, so always worry:) To reduce the worry level I would
confirm that there is really no current relation with an OID of
597597503. Still given that the query ran successfully on retry and that
it failed in the presence of a temporary table creation I would say the
evidence is that a temporary table disappeared out from under the query.

Cheers,
Steve

--
Adrian Klaver
adrian.klaver@aklaver.com

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general