SupportsNamespaces¶

SupportsNamespaces is an extension of the CatalogPlugin abstraction for catalogs with namespace support.

Contract (Subset)¶

Create Namespace¶

void createNamespace(
  String[] namespace,
  Map<String, String> metadata)

Creates a multi-part namespace in this catalog

Used when:

• DelegatingCatalogExtension is requested to createNamespace
• CREATE NAMESPACE command is executed

List Namespaces¶

String[][] listNamespaces()

Lists the top-level namespaces from this catalog

Used when:

• DelegatingCatalogExtension is requested to listNamespaces
• SHOW NAMESPACES command is executed

Load Namespace Metadata¶

Map<String, String> loadNamespaceMetadata(
  String[] namespace)

Loads metadata properties for the namespace

Used when:

• DelegatingCatalogExtension is requested to loadNamespaceMetadata
• SupportsNamespaces is requested to namespaceExists
• DESCRIBE NAMESPACE command is executed
• CatalogImpl is requested to getNamespace

Check If Namespace Exists¶

boolean namespaceExists(
  String[] namespace)

By default, namespaceExists tries to load the namespace metadata in this catalog. For a successful load, namespaceExists is positive (true).

Used when:

• CatalogManager is requested to setCurrentNamespace
• CatalogImpl is requested to databaseExists
• DelegatingCatalogExtension is requested to namespaceExists
• CREATE NAMESPACE command is executed
• DROP NAMESPACE command is executed

Implementations¶

• CatalogExtension
• JDBCTableCatalog
• V2SessionCatalog