org.apache.spark.sql.connector.catalog

Interface ViewCatalog

All Superinterfaces:

CatalogPlugin

@DeveloperApi
public interface ViewCatalog
extends CatalogPlugin

Catalog methods for working with views.

Field Summary

Fields

Modifier and Type	Field and Description
static String	PROP_COMMENT A reserved property to specify the description of the view.
static String	PROP_CREATE_ENGINE_VERSION A reserved property to specify the software version used to create the view.
static String	PROP_ENGINE_VERSION A reserved property to specify the software version used to change the view.
static String	PROP_OWNER A reserved property to specify the owner of the view.
static java.util.List<String>	RESERVED_PROPERTIES All reserved properties of the view.

Method Summary

Modifier and Type	Method and Description
View	alterView(Identifier ident, ViewChange... changes) Apply changes to a view in the catalog.
View	createView(Identifier ident, String sql, String currentCatalog, String[] currentNamespace, StructType schema, String[] queryColumnNames, String[] columnAliases, String[] columnComments, java.util.Map<String,String> properties) Create a view in the catalog.
boolean	dropView(Identifier ident) Drop a view in the catalog.
default void	invalidateView(Identifier ident) Invalidate cached view metadata for an identifier.
Identifier[]	listViews(String... namespace) List the views in a namespace from the catalog.
View	loadView(Identifier ident) Load view metadata by ident from the catalog.
void	renameView(Identifier oldIdent, Identifier newIdent) Rename a view in the catalog.
default boolean	viewExists(Identifier ident) Test whether a view exists using an identifier from the catalog.

Methods inherited from interface org.apache.spark.sql.connector.catalog.CatalogPlugin

defaultNamespace, initialize, name

Field Detail

PROP_COMMENT

static final String PROP_COMMENT

A reserved property to specify the description of the view.

See Also:

Constant Field Values

PROP_OWNER

static final String PROP_OWNER

A reserved property to specify the owner of the view.

See Also:

Constant Field Values

PROP_CREATE_ENGINE_VERSION

static final String PROP_CREATE_ENGINE_VERSION

A reserved property to specify the software version used to create the view.

See Also:

Constant Field Values

PROP_ENGINE_VERSION

static final String PROP_ENGINE_VERSION

A reserved property to specify the software version used to change the view.

See Also:

Constant Field Values

RESERVED_PROPERTIES

static final java.util.List<String> RESERVED_PROPERTIES

All reserved properties of the view.

Method Detail

listViews

Identifier[] listViews(String... namespace)
                throws org.apache.spark.sql.catalyst.analysis.NoSuchNamespaceException

List the views in a namespace from the catalog.

If the catalog supports tables, this must return identifiers for only views and not tables.

Parameters:

namespace - a multi-part namespace

Returns:

an array of Identifiers for views

Throws:

org.apache.spark.sql.catalyst.analysis.NoSuchNamespaceException - If the namespace does not exist (optional).

loadView

View loadView(Identifier ident)
       throws org.apache.spark.sql.catalyst.analysis.NoSuchViewException

Load view metadata by ident from the catalog.

If the catalog supports tables and contains a table for the identifier and not a view, this must throw NoSuchViewException.

Parameters:

ident - a view identifier

Returns:

the view description

Throws:

org.apache.spark.sql.catalyst.analysis.NoSuchViewException - If the view doesn't exist or is a table

invalidateView

default void invalidateView(Identifier ident)

Invalidate cached view metadata for an identifier.

If the view is already loaded or cached, drop cached data. If the view does not exist or is not cached, do nothing. Calling this method should not query remote services.

Parameters:

ident - a view identifier

viewExists

default boolean viewExists(Identifier ident)

Test whether a view exists using an identifier from the catalog.

If the catalog supports views and contains a view for the identifier and not a table, this must return false.

Parameters:

ident - a view identifier

Returns:

true if the view exists, false otherwise

createView

View createView(Identifier ident,
                String sql,
                String currentCatalog,
                String[] currentNamespace,
                StructType schema,
                String[] queryColumnNames,
                String[] columnAliases,
                String[] columnComments,
                java.util.Map<String,String> properties)
         throws org.apache.spark.sql.catalyst.analysis.ViewAlreadyExistsException,
                org.apache.spark.sql.catalyst.analysis.NoSuchNamespaceException

Create a view in the catalog.

Parameters:

ident - a view identifier

sql - the SQL text that defines the view

currentCatalog - the current catalog

currentNamespace - the current namespace

schema - the view query output schema

queryColumnNames - the query column names

columnAliases - the column aliases

columnComments - the column comments

properties - the view properties

Returns:

the view created

Throws:

org.apache.spark.sql.catalyst.analysis.ViewAlreadyExistsException - If a view or table already exists for the identifier

org.apache.spark.sql.catalyst.analysis.NoSuchNamespaceException - If the identifier namespace does not exist (optional)

alterView

View alterView(Identifier ident,
               ViewChange... changes)
        throws org.apache.spark.sql.catalyst.analysis.NoSuchViewException,
               IllegalArgumentException

Apply changes to a view in the catalog.

Implementations may reject the requested changes. If any change is rejected, none of the changes should be applied to the view.

Parameters:

ident - a view identifier

changes - an array of changes to apply to the view

Returns:

the view altered

Throws:

org.apache.spark.sql.catalyst.analysis.NoSuchViewException - If the view doesn't exist or is a table.

IllegalArgumentException - If any change is rejected by the implementation.

dropView

boolean dropView(Identifier ident)

Drop a view in the catalog.

If the catalog supports tables and contains a table for the identifier and not a view, this must not drop the table and must return false.

Parameters:

ident - a view identifier

Returns:

true if a view was deleted, false if no view exists for the identifier

renameView

void renameView(Identifier oldIdent,
                Identifier newIdent)
         throws org.apache.spark.sql.catalyst.analysis.NoSuchViewException,
                org.apache.spark.sql.catalyst.analysis.ViewAlreadyExistsException

Rename a view in the catalog.

If the catalog supports tables and contains a table with the old identifier, this throws NoSuchViewException. Additionally, if it contains a table with the new identifier, this throws ViewAlreadyExistsException.

If the catalog does not support view renames between namespaces, it throws UnsupportedOperationException.

Parameters:

oldIdent - the view identifier of the existing view to rename

newIdent - the new view identifier of the view

Throws:

org.apache.spark.sql.catalyst.analysis.NoSuchViewException - If the view to rename doesn't exist or is a table

org.apache.spark.sql.catalyst.analysis.ViewAlreadyExistsException - If the new view name already exists or is a table

UnsupportedOperationException - If the namespaces of old and new identifiers do not match (optional)