Schema and Ring Topology — Cassandra Driver 3.13.0 documentation (original) (raw)
Schemas¶
class 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.
Returns a CQL query string that can be used to recreate the entire keyspace, including user-defined types and tables.
Returns a CQL query string that can be used to recreate just this keyspace, not including user-defined types and tables.
class 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.
as_cql_query(formatted=False)[source]¶
Returns a CQL query that can be used to recreate this type. If formatted is set to True, extra whitespace will be added to make the query more readable.
class 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)
as_cql_query(formatted=False)[source]¶
Returns a CQL query that can be used to recreate this function. If formatted is set to True, extra whitespace will be added to make the query more readable.
class 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
as_cql_query(formatted=False)[source]¶
Returns a CQL query that can be used to recreate this aggregate. If formatted is set to True, extra whitespace will be added to make the query more readable.
class 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 theprimary_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.
Returns a string of CQL queries that can be used to recreate this table along with all indexes on it. The returned string is formatted to be human readable.
as_cql_query(formatted=False)[source]¶
Returns a CQL query that can be used to recreate this table (index creations are not included). If formatted is set to True, extra whitespace will be added to make the query human readable.
class 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
class 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.
Returns a CQL query that can be used to recreate this index.
Returns a CQL query string that can be used to recreate this index.
class 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.
as_cql_query(formatted=False)[source]¶
Returns a CQL query that can be used to recreate this function. If formatted is set to True, extra whitespace will be added to make the query more readable.
Tokens and Ring Topology¶
class cassandra.metadata. TokenMap[source]¶
Information about the layout of the ring.
token_class = None¶
A subclass of Token, depending on what partitioner the cluster uses.
ring = None¶
An ordered list of Token instances in the ring.
token_to_host_owner = None¶
A map of Token objects to the Host that owns that token.
tokens_to_hosts_by_ks = None¶
A map of keyspace names to a nested map of Token objects to sets of Host objects.
get_replicas(keyspace, token)[source]¶
Get a set of Host instances representing all of the replica nodes for a given Token.
class cassandra.metadata. Token[source]¶
Abstract class representing a token.
class cassandra.metadata. Murmur3Token(token)[source]¶
A token for Murmur3Partitioner.
token is an int or string representing the token.
class cassandra.metadata. MD5Token(token)[source]¶
A token for RandomPartitioner.
class cassandra.metadata. BytesToken(token)[source]¶
A token for ByteOrderedPartitioner.
classmethod from_string(token_string)[source]¶
token_string should be the string representation from the server.
cassandra.metadata. ReplicationStrategy¶
alias of _ReplicationStrategy
class cassandra.metadata. SimpleStrategy(options_map)[source]¶
replication_factor = None¶
The replication factor for this keyspace.
Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement.
class cassandra.metadata. NetworkTopologyStrategy(dc_replication_factors)[source]¶
dc_replication_factors = None¶
A map of datacenter names to the replication factor for that DC.
Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement.
class cassandra.metadata. LocalStrategy(options_map)[source]¶
Returns a string version of these replication options which are suitable for use in a CREATE KEYSPACE statement.