cassandra.metadata
- Schema and Ring Topology¶cassandra.metadata.
cql_keywords
¶Set of keywords in CQL.
Derived from …/cassandra/src/java/org/apache/cassandra/cql3/Cql.g
cassandra.metadata.
cql_keywords_unreserved
¶Set of unreserved keywords in CQL.
Derived from …/cassandra/src/java/org/apache/cassandra/cql3/Cql.g
cassandra.metadata.
cql_keywords_reserved
¶Set of reserved keywords in CQL.
cassandra.metadata.
Metadata
[source]¶Holds a representation of the cluster schema and topology.
cluster_name
= None¶The string name of the cluster.
partitioner
= None¶The string name of the partitioner for the cluster.
keyspaces
= None¶A map from keyspace names to matching KeyspaceMetadata
instances.
export_schema_as_string
()[source]¶Returns a string that can be executed as a query in order to recreate the entire schema. The string is formatted to be human readable.
get_replicas
(keyspace, key)[source]¶Returns a list of Host
instances that are replicas for a given
partition key.
cassandra.metadata.
KeyspaceMetadata
[source]¶A representation of the schema for a single keyspace.
name
= None¶The string name of the keyspace.
durable_writes
= True¶A boolean indicating whether durable writes are enabled for this keyspace or not.
replication_strategy
= None¶A ReplicationStrategy
subclass object.
tables
= None¶A map from table names to instances of TableMetadata
.
indexes
= None¶A dict mapping index names to IndexMetadata
instances.
user_types
= None¶A map from user-defined type names to instances of UserType
.
New in version 2.1.0.
functions
= None¶A map from user-defined function signatures to instances of Function
.
New in version 2.6.0.
aggregates
= None¶A map from user-defined aggregate signatures to instances of Aggregate
.
New in version 2.6.0.
views
= None¶A dict mapping view names to MaterializedViewMetadata
instances.
cassandra.metadata.
UserType
[source]¶A user defined type, as created by CREATE TYPE
statements.
User-defined types were introduced in Cassandra 2.1.
New in version 2.1.0.
keyspace
= None¶The string name of the keyspace in which this type is defined.
name
= None¶The name of this type.
field_names
= None¶An ordered list of the names for each field in this user-defined type.
field_types
= None¶An ordered list of the types for each field in this user-defined type.
cassandra.metadata.
Function
[source]¶A user defined function, as created by CREATE FUNCTION
statements.
User-defined functions were introduced in Cassandra 2.2
New in version 2.6.0.
keyspace
= None¶The string name of the keyspace in which this function is defined
name
= None¶The name of this function
argument_types
= None¶An ordered list of the types for each argument to the function
argument_names
= None¶An ordered list of the names of each argument to the function
return_type
= None¶Return type of the function
language
= None¶Language of the function body
body
= None¶Function body string
called_on_null_input
= None¶Flag indicating whether this function should be called for rows with null values (convenience function to avoid handling nulls explicitly if the result will just be null)
cassandra.metadata.
Aggregate
[source]¶A user defined aggregate function, as created by CREATE AGGREGATE
statements.
Aggregate functions were introduced in Cassandra 2.2
New in version 2.6.0.
keyspace
= None¶The string name of the keyspace in which this aggregate is defined
name
= None¶The name of this aggregate
argument_types
= None¶An ordered list of the types for each argument to the aggregate
state_func
= None¶Name of a state function
state_type
= None¶Type of the aggregate state
final_func
= None¶Name of a final function
initial_condition
= None¶Initial condition of the aggregate
return_type
= None¶Return type of the aggregate
cassandra.metadata.
TableMetadata
[source]¶A representation of the schema for a single table.
primary_key
¶A list of ColumnMetadata
representing the components of
the primary key for this table.
is_cql_compatible
¶A boolean indicating if this table can be represented as CQL in export
extensions
= None¶Metadata describing configuration for table extensions
keyspace_name
= None¶String name of this Table’s keyspace
name
= None¶The string name of the table.
partition_key
= None¶A list of ColumnMetadata
instances representing the columns in
the partition key for this table. This will always hold at least one
column.
clustering_key
= None¶A list of ColumnMetadata
instances representing the columns
in the clustering key for this table. These are all of the
primary_key
columns that are not in the partition_key
.
Note that a table may have no clustering keys, in which case this will be an empty list.
columns
= None¶A dict mapping column names to ColumnMetadata
instances.
indexes
= None¶A dict mapping index names to IndexMetadata
instances.
options
= None¶A dict mapping table option names to their specific settings for this table.
triggers
= None¶A dict mapping trigger names to TriggerMetadata
instances.
views
= None¶A dict mapping view names to MaterializedViewMetadata
instances.
cassandra.metadata.
ColumnMetadata
[source]¶A representation of a single column in a table.
table
= None¶The TableMetadata
this column belongs to.
name
= None¶The string name of this column.
cql_type
= None¶The CQL type for the column.
is_static
= False¶If this column is static (available in Cassandra 2.1+), this will
be True
, otherwise False
.
is_reversed
= False¶If this column is reversed (DESC) as in clustering order
cassandra.metadata.
IndexMetadata
[source]¶A representation of a secondary index on a column.
keyspace_name
= None¶A string name of the keyspace.
table_name
= None¶A string name of the table this index is on.
name
= None¶A string name for the index.
kind
= None¶A string representing the kind of index (COMPOSITE, CUSTOM,…).
index_options
= {}¶A dict of index options.
cassandra.metadata.
MaterializedViewMetadata
[source]¶A representation of a materialized view on a table
extensions
= None¶Metadata describing configuration for table extensions
keyspace_name
= None¶A string name of the view.
name
= None¶A string name of the view.
base_table_name
= None¶A string name of the base table for this view.
partition_key
= None¶A list of ColumnMetadata
instances representing the columns in
the partition key for this view. This will always hold at least one
column.
clustering_key
= None¶A list of ColumnMetadata
instances representing the columns
in the clustering key for this view.
Note that a table may have no clustering keys, in which case this will be an empty list.
columns
= None¶A dict mapping column names to ColumnMetadata
instances.
include_all_columns
= None¶A flag indicating whether the view was created AS SELECT *
where_clause
= None¶String WHERE clause for the view select statement. From server metadata
options
= None¶A dict mapping table option names to their specific settings for this view.
cassandra.metadata.
TokenMap
[source]¶Information about the layout of the ring.
cassandra.metadata.
Murmur3Token
(token)[source]¶A token for Murmur3Partitioner
.
token is an int or string representing the token.
cassandra.metadata.
ReplicationStrategy
¶alias of _ReplicationStrategy
cassandra.metadata.
SimpleStrategy
(options_map)[source]¶replication_factor
= None¶The replication factor for this keyspace.