Defines a new schema.
CREATE SCHEMA <schema_name> [AUTHORIZATION <username>] [<schema_element> [ ... ]] CREATE SCHEMA AUTHORIZATION <rolename> [<schema_element> [ ... ]]
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
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.
CREATE SEQUENCE, and
GRANTare accepted as clauses within
CREATE SCHEMA. Other kinds of objects may be created in separate commands after the schema is created.
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
CREATE SCHEMA 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 HAWQ.
The SQL standard specifies that the subcommands in
CREATE SCHEMA may appear in any order. The present HAWQ 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. HAWQ 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.