Re: ERROR: cache lookup failed for type 0

Hi Tom,

Thanks for your response.

None of the typeid atttypid fields were 0:

attrelid | attname | atttypid | attstattarget |
attlen | attnum | attndims | attcacheoff | atttypmod | attbyval |
attstorage | attalign | attnotnull | atthasdef | attisdropped |
attislocal | attinhcount
----------+---------------------------+----------+---------------+------
--+--------+----------+-------------+-----------+----------+------------
+----------+------------+-----------+--------------+------------+-------
------
167581 | tableoid | 26 | 0 |
4 | -7 | 0 | -1 | -1 | t | p
| i | t | f | f | t |
0
167581 | cmax | 29 | 0 |
4 | -6 | 0 | -1 | -1 | t | p
| i | t | f | f | t |
0
167581 | xmax | 28 | 0 |
4 | -5 | 0 | -1 | -1 | t | p
| i | t | f | f | t |
0
167581 | cmin | 29 | 0 |
4 | -4 | 0 | -1 | -1 | t | p
| i | t | f | f | t |
0
167581 | xmin | 28 | 0 |
4 | -3 | 0 | -1 | -1 | t | p
| i | t | f | f | t |
0
167581 | ctid | 27 | 0 |
6 | -1 | 0 | -1 | -1 | f | p
| s | t | f | f | t |
0
167581 | ropid | 23 | -1 |
4 | 1 | 0 | -1 | -1 | t | p
| i | t | f | f | f |
1
167581 | moid | 23 | -1 |
4 | 2 | 0 | -1 | -1 | t | p
| i | t | f | f | f |
1
167581 | tblock | 21 | -1 |
2 | 3 | 0 | -1 | -1 | t | p
| s | t | f | f | f |
1
167581 | pmtransmittedcarrierpower | 1016 | -1 |
-1 | 4 | 0 | -1 | -1 | f | x
| d | f | f | f | f |
1
167581 | pmaveragerssi | 1016 | -1 |
-1 | 5 | 0 | -1 | -1 | f | x
| d | f | f | f | f |
1
167581 | pm_count | 20 | -1 |
8 | 6 | 0 | -1 | -1 | f | p
| d | f | f | f | f |
1
(12 rows)

I don't know enough about this catalog table to say if anything else is
unusual about it. Comparing it with other tables that do not have a
problem did not reveal anything startling (to my eyes anyway).

The table is part of an inheritance structure. We are using inheritance
to partition the data based on a number of criteria. The top level
table ('carrier') has no records of it's own but defines the structure
of information stored in the table set. It's descendants (eg.
'carrier_on') are for either the original raw data, or data summarised
in one way or another. The third level tables (eg 'carrier_on_13642')
are divided into blocks of time.

All of the tables in this structure (and also parallel table structures
that we have) are linked back to two central tables via foreign keys on
the fields ropid and moid. There are a lot of relations which have these
fields as foreign references: this is causing another (unrelated I
think) problem: when we try to delete records from the table containing
the field ropid, it bombs with 'out of memory'.

=> \d pm.carrier_on_13642;
Table "pm.carrier_on_13642"
Column | Type | Modifiers
---------------------------+----------+-----------
ropid | integer | not null
moid | integer | not null
tblock | smallint | not null
pmtransmittedcarrierpower | bigint[] |
pmaveragerssi | bigint[] |
pm_count | bigint |
Indexes:
"carrier_on_13642_pkey" PRIMARY KEY, btree (ropid, moid)
"carrier_on_13642_moid_idx" btree (moid)
"carrier_on_13642_ropid_idx" btree (ropid)
Check constraints:
"carrier_on_13642_tblock_check" CHECK (tblock = 13642::smallint)
Foreign-key constraints:
"carrier_on_13642_moid_fkey" FOREIGN KEY (moid) REFERENCES
pm.mo(moid) ON DELETE CASCADE
"carrier_on_13642_ropid_fkey" FOREIGN KEY (ropid) REFERENCES
pm.rop(ropid) ON DELETE CASCADE
Inherits: carrier_on

Last night I did a pg_dump excluding this particular table. It failed,
complaining about another table pm.carrier_oo_13642 with the same error.
I then excluded that table also, after which the dump succeeded.

What does "ERROR: cache lookup failed for type 0" mean? I searched all
over the place for a good descripion but could not find one.

Regards // Mike

-----Original Message-----
From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
Sent: Friday, 25 May 2007 11:52 PM
To: Michael Harris (BR/EPA)
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] ERROR: cache lookup failed for type 0

"Michael Harris \(BR/EPA\)" <michael(dot)harris(at)ericsson(dot)com> writes:
> Whenever any kind of query is done on the table below, this is the
> result:

> ispdb_vxe=> select * from pm.carrier_on_13642;
> ERROR: cache lookup failed for type 0

Hmm, seems like something happened to your system catalogs, but where
exactly? Try this:

select * from pg_attribute where attrelid =
'pm.carrier_on_13642'::regclass;

and look whether any of the atttypid fields are zero. If so, does
anything else look wrong? If not, the problem must be further afield
--- have you got any triggers, check constraints, etc on this table?
(Can you do "\d" on it?)

regards, tom lane