CREATE SCHEMA

Function

CREATE SCHEMA creates a schema.

Named objects are accessed either by "qualifying" their names with the schema name as a prefix, or by setting a search path that includes the desired schema(s). When creating named objects, you can also use the schema name as a prefix.

Optionally, CREATE SCHEMA can include sub-commands to create objects within the new schema. The sub-commands are treated essentially the same as separate commands issued after creating the schema, If the AUTHORIZATION clause is used, all the created objects are owned by this user.

Precautions

As long as the current user has the CREATE permission, the user can create a schema.
The owner of an object created by a system administrator in a schema with the same name as a common user is the common user, not the system administrator.

Syntax

Create a schema based on a specified name:

      
           CREATE SCHEMA schema_name 
    [ AUTHORIZATION user_name ] [ WITH PERM SPACE 'space_limit'] [ schema_element [ ... ] ];
CREATE SCHEMA IF NOT EXISTS schema_name 
    [ AUTHORIZATION user_name ] [ WITH PERM SPACE 'space_limit'] ;

Create a schema based on a user name:

      
           CREATE SCHEMA AUTHORIZATION user_name [ WITH PERM SPACE 'space_limit'] [ schema_element [ ... ] ];
CREATE SCHEMA IF NOT EXISTS AUTHORIZATION user_name [ WITH PERM SPACE 'space_limit'] ;

Parameter Description

schema_name
Indicates the name of the schema to be created.
- The name must be unique,
- and cannot start with pg_.
Value range: a string. It must comply with the naming convention rule.
AUTHORIZATION user_name
Indicates the name of the user who will own this schema. If schema_name is not specified, user_name will be used as the schema name. In this case, user_name can only be a role name.

Value range: An existing user name/role.
WITH PERM SPACE 'space_limit'
Indicates the storage upper limit of the permanent table in the specified schema. If space_limit is not specified, the space is not limited.

Value range: A string consists of an integer and unit. The unit can be K/M/G/T/P currently. The unit of parsed value is K and cannot exceed the range that can be expressed in 64 bits, which is 1 KB to 9007199254740991 KB.
schema_element
Indicates an SQL statement defining an object to be created within the schema. Currently, only CREATE TABLE, CREATE VIEW, CREATE INDEX, CREATE PARTITION, and GRANT are accepted as clauses within CREATE SCHEMA.

Objects created by sub-commands are owned by the user specified by AUTHORIZATION.
IF NOT EXISTS
If IF NOT EXISTS is specified and no schema with the same name exists, a schema can be created. If a schema with the same name already exists during schema creation, the system will not report an error but will display a message indicating that the schema already exists and no further operations will be performed. When this parameter is used, the Schema_element subcommand cannot be included.

The IF NOT EXISTS parameter is supported only in 9.1.0 and later versions.

If objects in the schema on the current search path are with the same name, specify the schemas different objects are in. You can run the SHOW SEARCH_PATH command to check the schemas on the current search path.

Examples

-- Create the role1 role.

    
         CREATE ROLE role1 IDENTIFIED BY '{password}';

Create a schema named role1 for the role1 role. The owner of the films and winners tables created by the clause is role1.

    
         CREATE SCHEMA AUTHORIZATION role1
     CREATE TABLE films (title text, release date, awards text[])      
     CREATE VIEW winners AS         
     SELECT title, release FROM films WHERE awards IS NOT NULL;