gravitino.api.supports_schemas.SupportsSchemas¶

class gravitino.api.supports_schemas.SupportsSchemas¶

Bases: ABC

The Catalog interface to support schema operations. If the implemented catalog has schema semantics, it should implement this interface.

__init__()¶

Methods

`__init__`()
`alter_schema`(schema_name, *changes)	Apply the metadata change to a schema in the catalog.
`create_schema`(schema_name, comment, properties)	Create a schema in the catalog.
`drop_schema`(schema_name, cascade)	Drop a schema from the catalog.
`list_schemas`()	List schemas under the entity.
`load_schema`(schema_name)	Load metadata properties for a schema.
`schema_exists`(schema_name)	Check if a schema exists.

abstract alter_schema(schema_name: str, *changes: SchemaChange) → Schema¶

Apply the metadata change to a schema in the catalog.

Args:: schema_name: The name of the schema. changes: The metadata changes to apply.
Raises:: NoSuchSchemaException: If the schema does not exist.
Returns:: The altered schema.

abstract create_schema(schema_name: str, comment: str, properties: Dict[str, str]) → Schema¶

Create a schema in the catalog.

Args:: schema_name: The name of the schema. comment: The comment of the schema. properties: The properties of the schema.
Raises:: NoSuchCatalogException: If the catalog does not exist. SchemaAlreadyExistsException: If the schema already exists.
Returns:: The created schema.

abstract drop_schema(schema_name: str, cascade: bool) → bool¶

Drop a schema from the catalog. If cascade option is true, recursively drop all objects within the schema.

Args:: schema_name: The name of the schema. cascade: If true, recursively drop all objects within the schema.
Returns:: True if the schema exists and is dropped successfully, false otherwise.
Raises:: NonEmptySchemaException: If the schema is not empty and cascade is false.

abstract list_schemas() → List[str]¶

List schemas under the entity.

If an entity such as a table, view exists, its parent schemas must also exist and must be returned by this discovery method. For example, if table a.b.t exists, this method invoked as listSchemas(a) must return [b] in the result array

Raises:: NoSuchCatalogException: If the catalog does not exist.
Returns:: A list of schema names under the namespace.

abstract load_schema(schema_name: str) → Schema¶

Load metadata properties for a schema.

Args:: schema_name: The name of the schema.
Raises:: NoSuchSchemaException: If the schema does not exist (optional).
Returns:: A schema.

schema_exists(schema_name: str) → bool¶

Check if a schema exists.

If an entity such as a table, view exists, its parent namespaces must also exist. For example, if table a.b.t exists, this method invoked as schema_exists(a.b) must return true.

Args:: schema_name: The name of the schema.
Returns:: True if the schema exists, false otherwise.