CREATE TABLESPACE

Description

Creates a tablespace in a database.

Precautions

The system administrator or a user who inherits the gs_role_tablespace permission of the built-in role can create a tablespace.
Do not run CREATE TABLESPACE in a transaction block.
If executing CREATE TABLESPACE fails but the internal directory (or file) has been created, the directory (or file) will remain. You need to manually clear it before creating the tablespace again. If there are residual files of soft links for the tablespace in the data directory, delete the residual files, and then perform O&M operations.
CREATE TABLESPACE cannot be used for two-phase transactions. If it fails on some nodes, the execution cannot be rolled back.
You are advised not to use user-defined tablespaces in scenarios such as Huawei Cloud.
This is because user-defined tablespaces are usually used with storage media other than the main storage (storage device where the default tablespace is located, such as a disk) to isolate I/O resources that can be used by different services. Storage devices use standard configurations and do not have other available storage media in scenarios such as Huawei Cloud. If the user-defined tablespace is not properly used, the system cannot run stably for a long time and the overall performance is affected. Therefore, you are advised to use the default tablespace.

Syntax

    
         CREATE TABLESPACE tablespace_name
    [ OWNER user_name ] [ RELATIVE ] LOCATION 'directory' [ MAXSIZE 'space_size' ]
    [with_option_clause];

The with_option_clause syntax for creating a general tablespace is as follows:

    
         WITH ( {filesystem= { ' general ' | " general " | general } | address = { ' ip:port [, ... ] ' | " ip:port [, ... ] " } | cfgpath = { ' path ' | " path " } | storepath = { ' rootpath ' | " rootpath " } | random_page_cost = { ' value ' | " value " | value } | seq_page_cost = { ' value ' | " value " | value }}[, ... ])

Parameters

tablespace_name
Specifies name of a tablespace to be created.

The tablespace name must be distinct from the name of any existing tablespace in the cluster and cannot start with "pg", which are reserved for system catalog spaces.

Value range: a string. It must comply with the naming convention.
OWNER user_name
Specifies the name of the user who will own the tablespace. If omitted, the default owner is the current user.

Only system administrators can create tablespaces, but they can use the OWNER clause to assign ownership of tablespaces to non-Sysadmin administrators.

Value range: a string. It must be an existing user.
RELATIVE
If this parameter is specified, a relative path is used. The location directory is relative to each CN/DN data directory.

Directory hierarchy: relative path of the CNs and DNs directory /pg_location/. A relative path contains a maximum of two levels.

If this parameter is not specified, the absolute tablespace path is used. The location directory must be an absolute path.
LOCATION directory
Specifies the directory for the table space. When creating an absolute tablespace path, ensure that the directory meets the following requirements:
- The GaussDB system user must have the read and write permissions on the directory, and the directory must be empty. If the directory does not exist, the system automatically creates it.
- The directory must be an absolute path, and does not contain special characters, such as dollar sign ($) and greater-than sign (>).
- The directory cannot be specified under the database data directory.
- The directory must be a local path.
Value range: a string. It must be a valid directory.
MAXSIZE 'space_size'
Specifies the maximum value of the tablespace in a single DN.

Value range: a string consisting of a positive integer and unit. The unit can be KB, MB, GB, TB, or PB currently. The unit of parsed value is KB and cannot exceed the range that can be expressed in 64 bits, which is 1 KB to 9007199254740991 KB.
random_page_cost
Specifies the cost of randomly reading the page overhead.

Value range: 0 to 1.79769e+308

Default value: value of the GUC parameter random_page_cost
seq_page_cost
Specifies the cost of reading the page overhead in specified order.

Value range: 0 to 1.79769e+308

Default value: value of GUC parameter seq_page_cost

Examples

    
         -- Create a tablespace.
gaussdb=# CREATE TABLESPACE ds_location1 RELATIVE LOCATION 'test_tablespace/test_tablespace_1';

-- Create user joe.
gaussdb=# CREATE ROLE joe IDENTIFIED BY '********';

-- Create user jay.
gaussdb=# CREATE ROLE jay IDENTIFIED BY '*********';

-- Create a tablespace and set its owner to user joe.
gaussdb=# CREATE TABLESPACE ds_location2 OWNER joe RELATIVE LOCATION 'test_tablespace/test_tablespace_2';

-- Rename the ds_location1 tablespace to ds_location3.
gaussdb=# ALTER TABLESPACE ds_location1 RENAME TO ds_location3;

-- Change the owner of the ds_location2 tablespace.
gaussdb=# ALTER TABLESPACE ds_location2 OWNER TO jay;

-- Delete the tablespace.
gaussdb=# DROP TABLESPACE ds_location2;
gaussdb=# DROP TABLESPACE ds_location3;

-- Delete users.
gaussdb=# DROP ROLE joe;
gaussdb=# DROP ROLE jay;