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From Guy Incognito <dnd1...@gmail.com>
Subject Re: Replacing supercolumns with composite columns; Getting the equivalent of retrieving a list of supercolumns by name
Date Wed, 04 Jan 2012 20:09:42 GMT
i know it's a throwaway example, but i would probably structure your 
column the other way around in that case.

ie steve.4, steve.5, steve.6, greg.4, greg.6, greg.9.

and then do two slice queries, steve.4-steve.10, greg.4-greg.10.

On 04/01/2012 15:41, Jeremiah Jordan wrote:
> You can't use a slice range.  But you can query for the specific 
> columns.  "4.steve", "5.steve", "6.steve" ... "4.greg", "5.greg", 
> "6.greg".  Just have to ask for all of the possible columns you want.
>
> On 01/03/2012 04:31 PM, Stephen Pope wrote:
>>   The bonus you're talking about here, how do I apply that?
>>
>>   For example, my columns are in the form of number.id such as 
>> 4.steve, 4.greg, 5.steve, 5.george. Is there a way to query a slice 
>> of numbers with a list of ids? As in, I want all the columns with 
>> numbers between 4 and 10 which have ids steve or greg.
>>
>>   Cheers,
>>   Steve
>>
>> -----Original Message-----
>> From: Jeremiah Jordan [mailto:jeremiah.jordan@morningstar.com]
>> Sent: Tuesday, January 03, 2012 3:12 PM
>> To: user@cassandra.apache.org
>> Cc: Asil Klin
>> Subject: Re: Replacing supercolumns with composite columns; Getting 
>> the equivalent of retrieving a list of supercolumns by name
>>
>> The main issue with replacing super columns with composite columns 
>> right now is that if you don't know all your sub-column names you 
>> can't select multiple "super columns" worth of data in the same query 
>> without getting extra stuff.  You have to use a slice to get all 
>> subcolumns of a given super column, and you can't have disjoint 
>> slices, so if you want two super columns full, you have to get all 
>> the other stuff that is in between them, or make two queries.
>> If you know what all of the sub-column names are you can ask for all 
>> of the super/sub column pairs for all of the super columns you want 
>> and not get extra data.
>>
>> If you don't need to pull multiple super columns at a time with 
>> slices like that, then there isn't really an issue.
>>
>> A bonus of using composite keys like this, is that if there is a 
>> specific sub column you want from multiple super columns, you can 
>> pull all those out with a single multiget and you don't have to pull 
>> the rest of the columns...
>>
>> So there are pros and cons...
>>
>> -Jeremiah
>>
>>
>> On 01/03/2012 01:58 PM, Asil Klin wrote:
>>> I have a super columns family which I always use to retrieve a list of
>>> supercolumns(with all subcolumns) by name. I am looking forward to
>>> replace all SuperColumns in my schema with the composite columns.
>>>
>>> How could I design schema so that I could do the equivalent of
>>> retrieving a list of supercolumns by name, in case of using composite
>>> columns.
>>>
>>> (As of now I thought of using the supercolumn name as the first
>>> component of the composite name and the subcolumn name as 2nd
>>> component of composite name.)


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