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From David Strauss <da...@fourkitchens.com>
Subject Re: Cassandra Design or another solution
Date Mon, 05 Apr 2010 08:09:28 GMT
I need the question about monotonicity answered, too.

You should also know: Cassandra is not ideal for directly tracking
values you increment or decrement.

On 2010-04-05 08:04, JKnight JKnight wrote:
> Thanks for for reply, David.
> 
> I will tell more the detail about the system. My system is used to store
> the score (point) user earn when they play game.
> 
> "Mark" is the score.
> User's score changes when user win game, buy or sell anything.
> 
> Sorry I make a mistake. My data model is:
> 
> Mark{ //Column Family
>     gameId:{ //row key
>         mark_userId: ""// (column name : value),
>         mark2_userId2: ""
>     },
>     gameId2:{//row key
>         mark_userId: ""
>     }
> }
> 
> 
> On Sun, Apr 4, 2010 at 11:44 PM, David Strauss <david@fourkitchens.com
> <mailto:david@fourkitchens.com>> wrote:
> 
>     On 2010-04-05 02:48, JKnight JKnight wrote:
>     > I want to design the data storage to store user's mark for a large
>     > amount of user. When system run, user's mark changes frequently.
> 
>     What is a "mark"?
> 
>     > I want to list top 10 user have largest mark.
> 
>     Do the "marks" increase monotonically? What other properties do they
>     have?
> 
>     > Could we use Cassandra for store this data?
>     >
>     > Ex, here my Cassandra data model design:
>     > Mark{
>     >     userId{
>     >         mark_userId
>     >     },
>     > }
> 
>     I do not understand that notation. What parts are the CF, key/row, and
>     column?
> 
>     > When user's mark changes, we remove old mark_userId and add new
>     > mark_userId.
>     > Because user's mark change frequently and with large amount  of
>     user, I
>     > think Cassandra can not satisfy.
> 
>     On the contrary, Cassandra excels at tracking rapidly changing data and
>     even shards rows to scale I/O horizontally.
> 
>     --
>     David Strauss
>       | david@fourkitchens.com <mailto:david@fourkitchens.com>
>     Four Kitchens
>       | http://fourkitchens.com
>       | +1 512 454 6659 [office]
>       | +1 512 870 8453 [direct]
> 
> 
> 
> 
> -- 
> Best regards,
> JKnight


-- 
David Strauss
   | david@fourkitchens.com
   | +1 512 577 5827 [mobile]
Four Kitchens
   | http://fourkitchens.com
   | +1 512 454 6659 [office]
   | +1 512 870 8453 [direct]


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