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From kevin <kevincastigli...@gmail.com>
Subject Re: are columns of a supercolumn name sorted?
Date Mon, 26 Oct 2009 03:23:05 GMT
thanks for the hint. i have inserted 3 columns into a super column with
values 1, 2 and 3 in that order. but reversed variable in SliceRange has no
effect on the order of column received.
 reversed set to either True or False in SliceRange i get the column in the
same order. it is not getting reversed.
Can you tell what is wrong here?

>>> import lazyboy,time, pprint,uuid
>>> from cassandra import Cassandra
>>> from cassandra.ttypes import *
>>>
>>>
>>> client=lazyboy.connection.Client(['localhost:9160'])
>>> keyspace = "Keyspace1"
>>> key='mykeyx'
>>> column_path =
ColumnPath(column_family="Super1",column=uuid.uuid1().bytes,super_column='sc_2')
>>> client.insert(keyspace, key, column_path, '1', time.time(),
ConsistencyLevel.ONE);
>>> column_path =
ColumnPath(column_family="Super1",column=uuid.uuid1().bytes,super_column='sc_2')
>>> client.insert(keyspace, key, column_path, '2', time.time(),
ConsistencyLevel.ONE);
>>> column_path =
ColumnPath(column_family="Super1",column=uuid.uuid1().bytes,super_column='sc_2')
>>> client.insert(keyspace, key, column_path, '3', time.time(),
ConsistencyLevel.ONE);
>>> client.get_slice(keyspace, key, ColumnParent(column_family="Super1"),
SlicePredicate(slice_range=SliceRange(start="", finish="",reversed=True)),
ConsistencyLevel.ONE)
[ColumnOrSuperColumn(column=None, super_column=SuperColumn(name='sc_2',
columns=[Column(timestamp=1256527256,
name='\x93T\x12\x1c\xc1\xde\x11\xde\xa2;\x00%K\xcb\xc7F', value='1'),
Column(timestamp=1256527257,
name='\x93\x95`&\xc1\xde\x11\xde\xa4\x0c\x00%K\xcb\xc7F', value='2'),
Column(timestamp=1256527257,
name='\x93\xb1\x11T\xc1\xde\x11\xde\xae\xd7\x00%K\xcb\xc7F', value='3')]))]
>>> client.get_slice(keyspace, key, ColumnParent(column_family="Super1"),

SlicePredicate(slice_range=SliceRange(start="", finish="",reversed=False)),
ConsistencyLevel.ONE)
[ColumnOrSuperColumn(column=None, super_column=SuperColumn(name='sc_2',
columns=[Column(timestamp=1256527256,
name='\x93T\x12\x1c\xc1\xde\x11\xde\xa2;\x00%K\xcb\xc7F', value='1'),
Column(timestamp=1256527257,
name='\x93\x95`&\xc1\xde\x11\xde\xa4\x0c\x00%K\xcb\xc7F', value='2'),
Column(timestamp=1256527257,
name='\x93\xb1\x11T\xc1\xde\x11\xde\xae\xd7\x00%K\xcb\xc7F', value='3')]))]
>>>



On Sun, Oct 25, 2009 at 8:00 PM, Jonathan Ellis <jbellis@gmail.com> wrote:

> it's the "column" attribute of the column_path parameter.
>
> uuids have a specific meaning:
> http://en.wikipedia.org/wiki/Universally_Unique_Identifier
>
> test/system/test_server.py has an example of passing time uuids in python.
>
> On Sun, Oct 25, 2009 at 8:52 PM, kevin <kevincastiglione@gmail.com> wrote:
> > i tried the TimeUUIDType and I get the error. can you tell me which here
> > should be a UUID? what is time based uuid? and which parameter here
> should
> > be uuid?
> > thanks
> >
> >>>> import lazyboy,time, pprint
> >>>> from cassandra import Cassandra
> >>>> from cassandra.ttypes import *
> >>>>
> >>>>
> >>>> client=lazyboy.connection.Client(['localhost:9160'])
> >>>> keyspace = "Keyspace1"
> >>>> key='mykeyx'
> >>>> column_path =
> >>>> ColumnPath(column_family="Super1",column="x",super_column='sc_2')
> >>>> client.insert(keyspace, key, column_path, 'a', time.time(),
> >>>> ConsistencyLevel.ONE);
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in <module>
> >   File "/Users/kevin/common/lazyboy/connection.py", line 109, in func
> >     raise e
> > cassandra.ttypes.InvalidRequestException:
> InvalidRequestException(why='UUIDs
> > must be exactly 16 bytes')
> >
> > this is the config in storage-conf.xml
> >
> >       <ColumnFamily CompareWith="BytesType"
> >                     Name="Standard1"
> >                     FlushPeriodInMinutes="60"/>
> >       <ColumnFamily CompareWith="UTF8Type" Name="Standard2"/>
> >       <ColumnFamily CompareWith="TimeUUIDType" Name="StandardByUUID1"/>
> >       <ColumnFamily ColumnType="Super"
> >                     CompareWith="UTF8Type"
> >                     CompareSubcolumnsWith="TimeUUIDType"
> >                     Name="Super1"/>
> >
> >
> > On Sun, Oct 25, 2009 at 5:40 PM, Jonathan Ellis <jbellis@gmail.com>
> wrote:
> >>
> >> Sorry, the paragraph about subcolumns always being sorted by time is
> >> outdated.  (I've taken it out on the 0.4 branch now -- it was already
> >> gone in trunk.)  Read just below that about how comparewith and
> >> comparesubcolumnswith work.  Sounds like using TimeUUIDType for
> >> subcolumns is what you want (with the reverse option to slice, to get
> >> most-recent-first).
> >>
> >> On Sun, Oct 25, 2009 at 5:17 PM, kevin <kevincastiglione@gmail.com>
> wrote:
> >> > i am inserting three columns x,a,z into a super column named 'sc_2'.
> the
> >> > config file says that the columns of a super column are timesorted,
> but
> >> > when
> >> > i get_slice it is sorted by the name of the columns. how do i get it
> >> > time
> >> > sorted so that i get the most recently inserted/updated column first?
> >> > cassandra version apache-cassandra-incubating-0.4.1-bin.tar.gz, and
> >> > lazyboy
> >> > latest git clone.
> >> > thanks
> >> >
> >> >
> >> >>>> import lazyboy,time, pprint
> >> >>>> from cassandra import Cassandra
> >> >>>> from cassandra.ttypes import *
> >> >
> >> >
> >> >>>> client=lazyboy.connection.Client(['localhost:9160'])
> >> >>>> keyspace = "Keyspace1"
> >> >>>> key='mykeyx'
> >> >>>> column_path =
> >> >>>> ColumnPath(column_family="Super1",column="x",super_column='sc_2')
> >> >>>> client.insert(keyspace, key, column_path, 'a', time.time(),
> >> >>>> ConsistencyLevel.ONE);
> >> >>>> column_path =
> >> >>>> ColumnPath(column_family="Super1",column="a",super_column='sc_2')
> >> >>>> client.insert(keyspace, key, column_path, 'a', time.time(),
> >> >>>> ConsistencyLevel.ONE);
> >> >>>> column_path =
> >> >>>> ColumnPath(column_family="Super1",column="z",super_column='sc_2')
> >> >>>> client.insert(keyspace, key, column_path, 'a', time.time(),
> >> >>>> ConsistencyLevel.ONE);
> >> >
> >> >
> >> >>>> slice_range = SliceRange(start="", finish="")
> >> >>>> predicate = SlicePredicate(slice_range=slice_range)
> >> >>>> column_parent = ColumnParent(column_family="Super1")
> >> >>>> client.get_slice(keyspace, key, column_parent, predicate,
> >> >>>> ConsistencyLevel.ONE)
> >> > [ColumnOrSuperColumn(column=None,
> super_column=SuperColumn(name='sc_2',
> >> > columns=[Column(timestamp=1256512261, name='a', value='a'),
> >> > Column(timestamp=1256512252, name='x', value='a'),
> >> > Column(timestamp=1256512267, name='z', value='a')]))]
> >> >
> >
> >
>

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