本文整理汇总了Python中connection.Connection.describe_schema_versions方法的典型用法代码示例。如果您正苦于以下问题：Python Connection.describe_schema_versions方法的具体用法？Python Connection.describe_schema_versions怎么用？Python Connection.describe_schema_versions使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类connection.Connection的用法示例。
在下文中一共展示了Connection.describe_schema_versions方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: SystemManager
# 需要导入模块: from connection import Connection [as 别名]
# 或者: from connection.Connection import describe_schema_versions [as 别名]
#.........这里部分代码省略.........
def get_keyspace_properties(self, keyspace):
"""
Gets a keyspace's properties.
Returns a :class:`dict` with 'replication_factor', 'strategy_class',
and 'strategy_options' as keys.
"""
if keyspace is None:
keyspace = self._keyspace
ks_def = self._conn.describe_keyspace(keyspace)
return {'replication_factor': ks_def.replication_factor,
'replication_strategy': ks_def.strategy_class,
'strategy_options': ks_def.strategy_options}
def list_keyspaces(self):
""" Returns a list of all keyspace names. """
return [ks.name for ks in self._conn.describe_keyspaces()]
def describe_ring(self, keyspace):
""" Describes the Cassandra cluster """
return self._conn.describe_ring(keyspace)
def describe_cluster_name(self):
""" Gives the cluster name """
return self._conn.describe_cluster_name()
def describe_version(self):
""" Gives the server's API version """
return self._conn.describe_version()
def describe_schema_versions(self):
""" Lists what schema version each node has """
return self._conn.describe_schema_versions()
def describe_partitioner(self):
""" Gives the partitioner that the cluster is using """
part = self._conn.describe_partitioner()
return part[part.rfind('.') + 1: ]
def describe_snitch(self):
""" Gives the snitch that the cluster is using """
snitch = self._conn.describe_snitch()
return snitch[snitch.rfind('.') + 1: ]
def _system_add_keyspace(self, ksdef):
schema_version = self._conn.system_add_keyspace(ksdef)
self._wait_for_agreement()
return schema_version
def _system_update_keyspace(self, ksdef):
schema_version = self._conn.system_update_keyspace(ksdef)
self._wait_for_agreement()
return schema_version
def create_keyspace(self, name, replication_factor,
replication_strategy=SIMPLE_STRATEGY,
strategy_options=None):
"""
Creates a new keyspace. Column families may be added to this keyspace
after it is created using :meth:`create_column_family()`.
`replication_strategy` determines how replicas are chosen for this keyspace.示例2: SystemManager
# 需要导入模块: from connection import Connection [as 别名]
# 或者: from connection.Connection import describe_schema_versions [as 别名]
#.........这里部分代码省略.........
def alter_column(self, keyspace, column_family, column, value_type):
"""
Sets a data type for the value of a specific column.
`value_type` is a string that determines what type the column value will be.
By default, :const:`LONG_TYPE`, :const:`INTEGER_TYPE`,
:const:`ASCII_TYPE`, :const:`UTF8_TYPE`, :const:`TIME_UUID_TYPE`,
:const:`LEXICAL_UUID_TYPE` and :const:`BYTES_TYPE` are provided. Custom
types may be used as well by providing the class name; if the custom
comparator class is not in ``org.apache.cassandra.db.marshal``, the fully
qualified class name must be given.
"""
self._conn.set_keyspace(keyspace)
cfdef = self.get_keyspace_description(keyspace)[column_family]
if value_type.find('.') == -1:
value_type = 'org.apache.cassandra.db.marshal.%s' % value_type
matched = False
for c in cfdef.column_metadata:
if c.name == column:
c.validation_class = value_type
matched = True
break
if not matched:
cfdef.column_metadata.append(ColumnDef(column, value_type, None, None))
self._system_update_column_family(cfdef)
def create_index(self, keyspace, column_family, column, value_type,
index_type=KEYS_INDEX, index_name=None):
"""
Creates an index on a column.
This allows efficient for index usage via
:meth:`~pycassa.columnfamily.ColumnFamily.get_indexed_slices()`
`column` specifies what column to index, and `value_type` is a string
that describes that column's value's data type; see
:meth:`alter_column()` for a full description of `value_type`.
`index_type` determines how the index will be stored internally. Currently,
:const:`KEYS_INDEX` is the only option. `index_name` is an optional name
for the index.
Example Usage:
.. code-block:: python
>>> from pycassa.system_manager import *
>>> sys = SystemManager('192.168.2.10:9160')
>>> sys.create_index('Keyspace1', 'Standard1', 'birthdate', LONG_TYPE, 'bday_index')
>>> sys.close
"""
self._conn.set_keyspace(keyspace)
cfdef = self.get_keyspace_description(keyspace)[column_family]
if value_type.find('.') == -1:
value_type = 'org.apache.cassandra.db.marshal.%s' % value_type
coldef = ColumnDef(column, value_type, index_type, index_name)
matched = False
for c in cfdef.column_metadata:
if c.name == column:
c = coldef
matched = True
break
if not matched:
cfdef.column_metadata.append(coldef)
self._system_update_column_family(cfdef)
def drop_index(self, keyspace, column_family, column):
"""
Drops an index on a column.
"""
self._conn.set_keyspace(keyspace)
cfdef = self.get_keyspace_description(keyspace)[column_family]
matched = False
for c in cfdef.column_metadata:
if c.name == column:
c.index_type = None
c.index_name = None
matched = True
break
if matched:
self._system_update_column_family(cfdef)
def _wait_for_agreement(self):
while True:
versions = self._conn.describe_schema_versions()
if len(versions) == 1:
break
time.sleep(_SAMPLE_PERIOD)