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From Ertio Lew <ertio...@gmail.com>
Subject Re: Schema advice/help
Date Tue, 27 Mar 2012 09:31:23 GMT
@R. Verlangen:
You are suggesting to keep a single row for all activities & read all the
columns from the row & then filter, right!?

If done that way (instead of keeping it in 5 rows) then I would need to
retrieve 100s-200s of columns from single row rather than just 50 columns
if I keep in 5 rows.. Which of these two would be better ? More columns
from single row OR less columns from multiple rows ?

On Tue, Mar 27, 2012 at 2:27 PM, R. Verlangen <robin@us2.nl> wrote:

> You can just get a slice range with as start "userId:" and no end.
>
>
> 2012/3/27 Maciej Miklas <mac.miklas@googlemail.com>
>
>> multiget would require Order Preserving Partitioner, and this can lead to
>> unbalanced ring and hot spots.
>>
>> Maybe you can use secondary index on "itemtype" - is must have small
>> cardinality:
>> http://pkghosh.wordpress.com/2011/03/02/cassandra-secondary-index-patterns/
>>
>>
>>
>>
>> On Tue, Mar 27, 2012 at 10:10 AM, Guy Incognito <dnd1066@gmail.com>wrote:
>>
>>> without the ability to do disjoint column slices, i would probably use 5
>>> different rows.
>>>
>>> userId:itemType -> activityId
>>>
>>> then it's a multiget slice of 10 items from each of your 5 rows.
>>>
>>>
>>> On 26/03/2012 22:16, Ertio Lew wrote:
>>>
>>>> I need to store activities by each user, on 5 items types. I always
>>>> want to read last 10 activities on each item type, by a user (ie, total
>>>> activities to read at a time =50).
>>>>
>>>> I am wanting to store these activities in a single row for each user so
>>>> that they can be retrieved in single row query, since I want to read all
>>>> the last 10 activities on each item.. I am thinking of creating composite
>>>> names appending "itemtype" : "activityId"(activityId is just timestamp
>>>> value) but then, I don't see about how to read the last 10 activities from
>>>> all itemtypes.
>>>>
>>>> Any ideas about schema to do this better way ?
>>>>
>>>
>>>
>>
>
>
> --
> With kind regards,
>
> Robin Verlangen
> www.robinverlangen.nl
>
>

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