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From Roshan Dawrani <roshandawr...@gmail.com>
Subject Re: I have TimeUUID sorted keys. Can I get the range query return rows in the same order as sorted keys?
Date Mon, 27 Dec 2010 17:51:24 GMT
Thanks for the references. I will have a look at them to become familiar
with them.

But for now, my rather simplistic need is fulfilled by first getting the
time-sorted keys from sub-columns and then arranging the result of a
multi_get_slice_query in the same order at the app level.

For now I don't want to get into OPP to achieve it - as I see some "be
careful" annotations with it. Nice and simple to start in Cassandra field.
:-) Thanks again for the information though.


On Mon, Dec 27, 2010 at 11:15 PM, Tyler Hobbs <tyler@riptano.com> wrote:

> Might as well link to this nice article for any discussions of OPP vs RP:
>
>
> http://ria101.wordpress.com/2010/02/22/cassandra-randompartitioner-vs-orderpreservingpartitioner/
>
> - Tyler
>
>
> On Mon, Dec 27, 2010 at 11:18 AM, Narendra Sharma <
> narendra.sharma@gmail.com> wrote:
>
>> You will need to use OPP to perform range scans. Look for Range Queries on
>> http://wiki.apache.org/cassandra/DataModel
>>
>> Look at this to understand why range queries are not supported for
>> RamdomPartitioner (https://issues.apache.org/jira/browse/CASSANDRA-1750)
>>
>> Thanks,
>> Naren
>>
>>
>> On Mon, Dec 27, 2010 at 8:35 AM, Roshan Dawrani <roshandawrani@gmail.com>wrote:
>>
>>> I had seen RangeSlicesQuery, but I didn't notice that I could also give a
>>> key range there.
>>>
>>> How does a KeyRange work? Doesn't it need some sort from the partitioner
>>> - whether that is order preserving or not?
>>>
>>> I couldn't be sure of a query that was based on order of the rows in the
>>> column family, so I didn't explore that much.
>>>
>>>
>>>
>>> On Mon, Dec 27, 2010 at 9:55 PM, Narendra Sharma <
>>> narendra.sharma@gmail.com> wrote:
>>>
>>>> Did you look at get_range_slices? Once you get the columns from super
>>>> column, pick the first and last to form the range and fire the
>>>> get_range_slice.
>>>>
>>>> Thanks,
>>>> -Naren
>>>>
>>>>
>>>> On Mon, Dec 27, 2010 at 6:12 AM, Roshan Dawrani <
>>>> roshandawrani@gmail.com> wrote:
>>>>
>>>>> This silly question is retrieved back with apology. There couldn't be
>>>>> anything easier to handle at the application level.
>>>>>
>>>>> rgds,
>>>>> Roshan
>>>>>
>>>>>
>>>>> On Mon, Dec 27, 2010 at 9:04 AM, Roshan Dawrani <
>>>>> roshandawrani@gmail.com> wrote:
>>>>>
>>>>>> Hi,
>>>>>> I have the following 2 column families - one being used to store
full
>>>>>> rows for an entity and other is an index table for having the TimeUUID
>>>>>> sorted row keys.
>>>>>>
>>>>>> I am able to query the TimeUUID columns under the super column fine.
>>>>>> But now I need to go to main CF and get the data and I want the rows
in the
>>>>>> same time order as the keys.
>>>>>>
>>>>>> I am using MultiGetSliceQuery to query the main entity data for the
>>>>>> sorted keys, but the rows don't come back in the same order, which
defeats
>>>>>> the purpose of storing the time sorted subcolumns. I suppose for
each key, I
>>>>>> can fire an individual SliceQuery, but that does not look efficient
to me. I
>>>>>> do want to fire a range query.
>>>>>>
>>>>>> MainEntityCF {
>>>>>>          TimeUUIDKeyA: ["Col1" : "Val1", "Col2" : "Val2", "Col3"
:
>>>>>> "Val3"]
>>>>>>          TimeUUIDKeyX: ["Col1" : "Val1", "Col2" : "Val2", "Col3"
:
>>>>>> "Val3"]
>>>>>>          TimeUUIDKeyB: ["Col1" : "Val1", "Col2" : "Val2", "Col3"
:
>>>>>> "Val3"]
>>>>>>          TimeUUIDKeyY: ["Col1" : "Val1", "Col2" : "Val2", "Col3"
:
>>>>>> "Val3"]
>>>>>> }
>>>>>> MainEntityCF_Index {
>>>>>>       "SomeSuperColumn": [TimeUUIDKeyA:null, TimeUUIDKeyB:null,
>>>>>> TimeUUIDKeyX:null, TimeUUIDKeyY:null]
>>>>>> }
>>>>>>
>>>>>> --
>>>>>> Roshan
>>>>>> Blog: http://roshandawrani.wordpress.com/
>>>>>> Twitter: @roshandawrani <http://twitter.com/roshandawrani>
>>>>>> Skype: roshandawrani
>>>>>>
>>>>>>
>>>>
>>>
>>>
>>> --
>>> Roshan
>>> Blog: http://roshandawrani.wordpress.com/
>>> Twitter: @roshandawrani <http://twitter.com/roshandawrani>
>>> Skype: roshandawrani
>>>
>>>
>>
>


-- 
Roshan
Blog: http://roshandawrani.wordpress.com/
Twitter: @roshandawrani <http://twitter.com/roshandawrani>
Skype: roshandawrani

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