Обсуждение: Help! pg_dump: Error message from server: ERROR: cache lookup failed for type 19

i use the slony for replication of postgresql database. it work fine some day.
After i use the slony command to delete the replication node, pg_dump does not work, the error message is:
pg_dump: schema with OID 73033 does not exist

Then i delete the name space of slony in  pg_namespace, and pg_dump does not work.
So i delete the data of the name space in pg_class, pg_type, the command is:
DELETE FROM pg_class where relnamespace=73033
DELETE FROM pg_type where relnamespace=73033

i got the error message:
pg_dump: Error message from server: ERROR:  cache lookup failed for type 19

How to fix it? How to recovery the database?
thanks!


wu.xia

On 11/09/10 14:21, 夏武 wrote:
> i use the slony for replication of postgresql database. it work fine
> some day.
> After i use the slony command to delete the replication node, pg_dump
> does not work, the error message is:
> *pg_dump: schema with OID 73033 does not exist*
>
> Then i delete the name space of slony in  pg_namespace, and pg_dump does
> not work.
> So i delete the data of the name space in pg_class, pg_type, the command is:
> *DELETE FROM pg_class where relnamespace=73033*
> *DELETE FROM pg_type where relnamespace=73033*

That might not have been a very good idea. You're really not meant to go
messing with the catalog unless you *really* know what you are doing.

It sounds like you have a very badly messed up catalog. You will need to
find a way to dump your database so you can drop it, re-create it and
reload it.

> i got the error message:
> pg_dump: Error message from server: ERROR:  cache lookup failed for type 19

> How to fix it? How to recovery the database?

Your best chance is to do a pg_dump of each table, one by one, using the
"--table" option. Find out which table or tables are failing.

Once you know that, post here with the table definition, the exact
error, and the output of "select * from pg_class" and "select * from
pg_type". Somebody might be able to help you if there's enough information.

Alternately, you might be able to extract the data from the problem
table(s) using  the \copy command from psql. Then you can re-create them
in the new database and re-load their contents with \copy .

--
Craig Ringer

Tech-related writing: http://soapyfrogs.blogspot.com/

I reconvery it  by \copy command.
thanks very much.

On 14/09/2010 11:02 AM, 夏武 wrote:
> I reconvery it  by \copy command.
> thanks very much.

Glad to help.

In future, it might be a good idea to:

- Keep regular pg_dump backups; and
- Avoid trying to alter the system catalogs

With Slony you can never completely avoid needing to mess with the
catalogs, as it seems to be able to get things into a nasty state
sometimes. However, if you do have to do catalog work it's a good idea
to ask for help here *before* doing anything, because it'll be easier to
fix if you haven't deleted catalog entries etc.

--
Craig Ringer

Tech-related writing at http://soapyfrogs.blogspot.com/