CREATE TABLESPACE — define a new tablespace
CREATE TABLESPACEtablespace_name[ OWNER {new_owner| CURRENT_USER | SESSION_USER } ] LOCATION 'directory' [ WITH (tablespace_option=value[, ... ] ) ]
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.
A tablespace cannot be used independently of the cluster in which it is defined; see Section 20.6.
tablespace_name
The name of a tablespace to be created. The name cannot
begin with pg_, as such names
are reserved for system tablespaces.
user_nameThe 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.
directory
The directory that will be used for the tablespace. The directory
must exist (CREATE TABLESPACE will not create it),
should be empty, and must be owned by the
LightDB system user. The directory must be
specified by an absolute path name.
tablespace_option
A tablespace parameter to be set or reset. Currently, the only
available parameters are seq_page_cost,
random_page_cost, effective_io_concurrency
and maintenance_io_concurrency.
Setting these values for a particular tablespace will override the
planner's usual estimate of the cost of reading pages from tables in
that tablespace, and the executor's prefetching behavior, as established
by the configuration parameters of the
same name (see seq_page_cost,
random_page_cost,
effective_io_concurrency,
maintenance_io_concurrency). This may be useful if
one tablespace is located on a disk which is faster or slower than the
remainder of the I/O subsystem.
Tablespaces are only supported on systems that support symbolic links.
CREATE TABLESPACE cannot be executed inside a transaction
block.
To create a tablespace dbspace at file system location
/data/dbs, first create the directory using operating
system facilities and set the correct ownership:
mkdir /data/dbs chown lightdb:lightdb /data/dbs
Then issue the tablespace creation command inside LightDB:
CREATE TABLESPACE dbspace LOCATION '/data/dbs';
To create a tablespace owned by a different database user, use a command like this:
CREATE TABLESPACE indexspace OWNER genevieve LOCATION '/data/indexes';
CREATE TABLESPACE is a LightDB
extension.