On 21.09.2013 20:16, jan.m...@inf-it.com wrote:
today I tried to upgrade from 9.2 to 9.3 (pg_upgradecluster 9.2 main) and
the upgrade of one of my databases failed with the following error: "ERROR:
new row for relation ... violates check constraint ...".

I created an example to reproduce this bug:

http://www.inf-it.com/fixes/postgres-bugreport2/schema.sql

The problem is that when the database is dumped with pg_dump and reloaded, the activity table is loaded first, and codebook table second. The check constraint checks that when a row is inserted into activity table, the corresponding row exists in codebook table, which clearly isn't true if the activity table is loaded first and the codebook table is still empty. The system doesn't know about that dependency since it's all implemented in the PL/pgSQL code. With a constraint like that, you would also get an unrestorable dump if you e.g deleted a row from codebook table after loading the activities.

Usually you would implement a schema like that using foreign keys. That would be less code, and the system would automatically get the dump order correct. I would recommend that over a check constraint, if possible.

As a work-around, you can drop the constraints from the database before upgrading, and restore them afterwards. The problem isn't really related to upgrade per se, BTW. Running pg_dump + restore even on the same version will give you the same error.

- Heikki


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