CREATE TABLESPACE registers a new cluster-wide tablespace. The tablespace name must be distinct from the name of any existing tablespace in the database cluster.
A tablespace allows superusers to define an alternative location on the file system where the data files containing database objects (such as tables and indexes) may reside.
A user with appropriate privileges can pass tablespacename to CREATE DATABASE, CREATE TABLE, CREATE INDEX or ADD CONSTRAINT to have the data files for these objects stored within the specified tablespace.
The name of a tablespace to be created. The name cannot begin with pg_, as such names are reserved for system tablespaces.
The name of the user who will own the tablespace. If omitted, defaults to the user executing the command. Only superusers may create tablespaces, but they can assign ownership of tablespaces to non-superusers.
The directory that will be used for the tablespace. The directory must be empty and must be owned by the PostgreSQL system user. The directory must be specified by an absolute path name.
Create a tablespace dbspace at /data/dbs:
CREATE TABLESPACE dbspace LOCATION '/data/dbs';
Create a tablespace indexspace at /data/indexes owned by user genevieve:
CREATE TABLESPACE indexspace OWNER genevieve LOCATION '/data/indexes';
This may be obvious to most, but took me a couple of minutes - the directory you're creating the tablespace in has to be owned by the user the database is running as ( e.g. on gentoo: postgres:postgres )