postgresql how to backup and overwrite specific tables - postgresql

Question

I need to be able to somehow get a set of tables from my dev db into my production db. I've just been creating a dump file from the dev db and using pg_restore on the production db. The problem now is that I need to preserve one table(called users) on the production db while replacing the others
I think I have the dump properly from this command
pg_dump -Fc --no-acl --no-owner -h localhost -U <USER> --exclude-table=users* --data-only <DB NAME> > test.dump
But I can't get the restore part to work. I tried the following command
pg_restore -Fc --no-acl --no-owner -h <PROD HOST> -U <USER> -d <DB NAME> -p <PORT> <FILE LOCATION>
BUt I get the following errors
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 2009; 0 121384 TABLE DATA idx_descs Jason
pg_restore: [archiver (db)] COPY failed for table "idx_descs": ERROR: duplicate key value violates unique constraint "idx_descs_pkey"
DETAIL: Key (id)=(6) already exists.
CONTEXT: COPY idx_descs, line 1
It seems like for the tables I'm trying to overwrite, it is just trying to append the data and running into trouble because there are now duplicate primary keys. Any Ideas how to do this? Thanks

Answer 1

So you need to reassign primary keys?
You could try restoring to a temporary table (say for instance, in failing case: idx_desc_temp), then doing something like:
with t as ( select * from idx_descs_temp )
insert into idx_descs
select id + 100000 [or whatever], [other fields] from t;
Afterwards you need to reset sequences (if applicable -- fill in sequence name....):
select setval( 'idx_descs_id_seq'::regclass, 100000 + [suitable increment]);
If you have a large # of tables you could try to automate using the system catalog.
Note though that you also have to renumber foreign key refs. Possibly less pain would be to move data in production db first. If you are using an ORM, you could also automate via application APIs.