Defines a new schema.
CREATE SCHEMA <schema_name> [AUTHORIZATION <username>]
[<schema_element> [ ... ]]
CREATE SCHEMA AUTHORIZATION <rolename> [<schema_element> [ ... ]]
CREATE SCHEMA IF NOT EXISTS <schema_name> [ AUTHORIZATION <user_name> ]
CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <user_name>
CREATE SCHEMA
enters a new schema into the current database. The schema name must be distinct from the name of any existing schema in the current database.
A schema is essentially a namespace: it contains named objects (tables, data types, functions, and operators) whose names may duplicate those of other objects existing in other schemas. 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). A CREATE
command specifying an unqualified object name creates the object in the current schema (the one at the front of the search path, which can be determined with the function current_schema
).
Optionally, CREATE SCHEMA
can include subcommands to create objects within the new schema. The subcommands are treated essentially the same as separate commands issued after creating the schema, except that if the AUTHORIZATION
clause is used, all the created objects will be owned by that role.
pg_
, as such names are reserved for system catalog schemas.
An SQL statement defining an object to be created within the schema. Currently, only CREATE TABLE
, CREATE VIEW
, CREATE INDEX
, CREATE SEQUENCE
, CREATE TRIGGER
and GRANT
are accepted as clauses within CREATE SCHEMA
. Other kinds of objects may be created in separate commands after the schema is created.
NoteGreenplum Database does not support triggers.
IF NOT EXISTS
To create a schema, the invoking user must have the CREATE
privilege for the current database or be a superuser.
Create a schema:
CREATE SCHEMA myschema;
Create a schema for role joe
(the schema will also be named joe
):
CREATE SCHEMA AUTHORIZATION joe;
Create a schema named test
that will be owned by user joe
, unless there already is a schema named test
. (It does not matter whether joe
owns the pre-existing schema.)
CREATE SCHEMA IF NOT EXISTS test AUTHORIZATION joe;
The SQL standard allows a DEFAULT CHARACTER SET
clause in CREATE SCHEMA
, as well as more subcommand types than are presently accepted by Greenplum Database.
The SQL standard specifies that the subcommands in CREATE SCHEMA
may appear in any order. The present Greenplum Database implementation does not handle all cases of forward references in subcommands; it may sometimes be necessary to reorder the subcommands in order to avoid forward references.
According to the SQL standard, the owner of a schema always owns all objects within it. Greenplum Database allows schemas to contain objects owned by users other than the schema owner. This can happen only if the schema owner grants the CREATE
privilege on the schema to someone else, or a superuser chooses to create objects in it.
The IF NOT EXISTS
option is a Greenplum Database extension.
Parent topic: SQL Commands