will pg_restore overwrite the existing tables?

问题:

Say I have two host servers s1 and s2. In both the servers i have a schema named n1, now i have made some changes to some of the tables present in schema n1 of s1. I want the same change to be done to schema n1 of server s2. what i am planning to do is to take a backup of the schema n1 of server s1 using pg_dump and restore in the server s2 using pg_restore. Now my question is ,since there is already the same schema n1 in the server s2 with the same set of tables. what the restore process will do? will it overwrite the existing tables or should i drop the existing schema of server s2 and restore it using the dump from server s1?

回答1:

If you use the --clean option of pg_restore, the old tables will be dropped before the new ones are created.

If you do not use the --clean option, you will get an error message that the table already exists, but pg_restore will continue processing unless you use the --exit-on-error option.