Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.
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) can reside.
A user with appropriate privileges can pass tablespace_name 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 can create tablespaces, but they can assign ownership of tablespaces to non-superusers.
The directory that will be used for the tablespace. The directory should be empty and must be owned by the Postgres-XC system user. The directory must be specified by an absolute path name.
Tablespaces are only supported on systems that support symbolic links.
CREATE TABLESPACE cannot be executed inside a transaction block.
Note: The following description applies only to Postgres-XC
Postgres-XC assigns the same path to a tablespace for all the Coordinators and Datanodes. So when creating a tablespace, user needs to have permission to the same location path on all the servers involved in the cluster.
CREATE TABLESPACE can be run with EXECUTE DIRECT to control tablespace existence on remote nodes. This works for both remote Coordinators and Datanodes but not on this operation is not authorized on node where application client is connected.