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CREATE NAMESPACE, DROP NAMESPACE

v3.0.0

Group tables that belong together under a namespace.

In this article

A namespace groups tables that belong together, such as tables that are joined or read together. It is a label for that grouping and nothing else: it is not a separate storage area, it does not scope transactions, and it does not let two tables share a name.

Syntax

CREATE NAMESPACE <name>
DROP NAMESPACE <name>

Examples

On a new, empty instance:

kdbs> CREATE NAMESPACE ops
CREATED NAMESPACE ops oid=4000

kdbs> SHOW NAMESPACES
sys public ops

kdbs> CREATE TABLE ops.gates (id int64, flight_id int64)
CREATED oid=4001

kdbs> DROP NAMESPACE ops
                     ^
ERR byte 15: namespace oid 4000 cannot be dropped: relation 'gates' is still in it

A qualifier that does not match where the table lives is refused, and the error says where it is. Here a namespace cargo also exists:

kdbs> SELECT * FROM cargo.gates
                    ^
ERR byte 14: no relation 'cargo.gates'; 'gates' is in namespace 'ops'

A qualifier that names no namespace at all is refused as no namespace named '<name>'.

Remarks

  • Table names are unique across the whole instance. At CREATE TABLE ns.t, the qualifier chooses the namespace; everywhere else it is only checked.
  • An unqualified name always means what it meant before namespaces existed.
  • sys (the catalog views) and public (the default for an unqualified CREATE TABLE) are reserved and cannot be created or dropped.
  • A namespace is never created by being mentioned. CREATE TABLE opz.gates with no opz namespace is an error, so a typo cannot create a second namespace.
  • DROP NAMESPACE is refused while the namespace holds any table, and the error names one of them. There is no CASCADE.

Limitations

  • Today a namespace changes no result and no cost. The engine records the grouping for future use.
  • public.t is not accepted as a spelling of t.

Sandbox: namespaces are disabled in the browser sandbox.