Postgresql – Monitoring PostgreSQL backup

There are various ways to set the search_path in PostgreSQL.

To diagnose, log into the same database as the same superuser and check:

SHOW search_path;

If it contains dbms_sql, then check your postgresql.conf, databse and role settings to find where it came from.

Use any editor or for instance grep on in a Linux shell to audit postgresql.conf:

grep 'search_path' /your/path/to/postgresql.conf

To check on database and role settings, use the default command line client psql or a graphical GUI like pgAdmin.

In pgAdmin you just select the object in the object browser to see all settings in the SQL pane.

In psql, use

\drds superuser

to see settings for this role. And

\drds '' db_name

to see settings for the database. Or just

\drds 

to see all settings for all roles and databases.

The error is harmless but to get rid of it, I think you need to break this restore into two commands, as in:

dropdb -U postgres mydb && \
 pg_restore --create --dbname=postgres --username=postgres pg_backup.dump

The --clean option in pg_restore doesn't look like much but actually raises non-trivial problems.

For versions up to 9.1

The combination of --create and --clean in pg_restore options used to be an error in older PG versions (up to 9.1). There is indeed some contradiction between (quoting the 9.1 manpage):

--clean Clean (drop) database objects before recreating them

and

--create Create the database before restoring into it.

Because what's the point of cleaning inside a brand-new database?

Starting from version 9.2

The combination is now accepted and the doc says this (quoting the 9.3 manpage):

--clean Clean (drop) database objects before recreating them. (This might generate some harmless error messages, if any objects were not present in the destination database.)

--create Create the database before restoring into it. If --clean is also specified, drop and recreate the target database before connecting to it.

Now having both together leads to this kind of sequence during your restore:

DROP DATABASE mydb;
...
CREATE DATABASE mydb WITH TEMPLATE = template0... [other options]
...
CREATE SCHEMA public;
...
CREATE TABLE...

There is no DROP for each individual object, only a DROP DATABASE at the beginning. If not using --create this would be the opposite.

Anyway this sequence raises the error of public schema already existing because creating mydb from template0 has imported it already (which is normal, it's the point of a template database).

I'm not sure why this case is not handled automatically by pg_restore. Maybe this would cause undesirable side-effects when an admin decides to customize template0 and/or change the purpose of public, even if we're not supposed to do that.