class Metadata

Clears the internal state related to the prepared statements. Following calls to the Client using the prepare flag will re-prepare the statements.

Gets a definition of CQL aggregate for a given name and signature.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same aggregate definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace
name	String	Name of the aggregate
signature	Array<String> or Array<{code, info}>	Array of types of the parameters.
callback optional	function	The callback with the err as a first parameter and the Aggregate as second parameter.

Gets the definition of CQL aggregate for a given name.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same aggregates definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace
name	String	Name of the Function
callback optional	function	The callback with the err as a first parameter and the array of Aggregate as second parameter.

Gets a definition of CQL function for a given name and signature.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same function definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace
name	String	Name of the Function
signature	Array<String> or Array<{code, info}>	Array of types of the parameters.
callback optional	function	The callback with the err as a first parameter and the SchemaFunction as second parameter.

Gets the definition of CQL functions for a given name.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same function definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace.
name	String	Name of the Function.
callback optional	function	The callback with the err as a first parameter and the array of SchemaFunction as second parameter.

Gets the definition of a CQL materialized view for a given name.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

Note that, unlike the rest of the Metadata methods, this method does not cache the result for following calls, as the current version of the Cassandra native protocol does not support schema change events for materialized views. Each call to this method will produce one or more queries to the cluster.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace
name	String	Name of the materialized view
callback optional	function	The callback with the err as a first parameter and the MaterializedView as second parameter.

Gets the host list representing the replicas that contain such partition.

It uses the pre-loaded keyspace metadata to retrieve the replicas for a token for a given keyspace. When the keyspace metadata has not been loaded, it returns null.

Parameters:

Name	Type	Description
keyspaceName	String
tokenBuffer	Buffer

Returns:

Type	Description
Array

Gets the definition of a table.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same table definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace.
name	String	Name of the Table.
callback optional	function	The callback with the err as a first parameter and the TableMetadata as second parameter.

Gets the trace session generated by Cassandra when query tracing is enabled for the query. The trace itself is stored in Cassandra in the sessions and events table in the system_traces keyspace and can be retrieve manually using the trace identifier.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

Parameters:

Name	Type	Description
traceId	Uuid	Identifier of the trace session.
callback optional	function	The callback with the err as first parameter and the query trace as second parameter.

Gets the definition of an user-defined type.

If a callback is provided, the callback is invoked when the metadata retrieval completes. Otherwise, it returns a Promise.

When trying to retrieve the same UDT definition concurrently, it will query once and invoke all callbacks with the retrieved information.

Parameters:

Name	Type	Description
keyspaceName	String	Name of the keyspace.
name	String	Name of the UDT.
callback optional	function	The callback to invoke when retrieval completes.

Gets the keyspace metadata information and updates the internal state of the driver.

If a callback is provided, the callback is invoked when the keyspaces metadata refresh completes. Otherwise, it returns a Promise.

Parameters:

Name	Type	Description
name	String	Name of the keyspace.
callback optional	function	Optional callback.

Gets the metadata information of all the keyspaces and updates the internal state of the driver.

If a callback is provided, the callback is invoked when the keyspace metadata refresh completes. Otherwise, it returns a Promise.

Parameters:

Name	Type	Description
waitReconnect optional	Boolean or function	Determines if it should wait for reconnection in case the control connection is not connected at the moment. Default: true.
callback optional	function	Optional callback.