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 <da...@fourkitchens.com
> <mailto:da...@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
> | da...@fourkitchens.com <mailto:da...@fourkitchens.com>
> Four Kitchens
> | http://fourkitchens.com
> | +1 512 454 6659 [office]
> | +1 512 870 8453 [direct]
>
>
>
>
> --
> Best regards,
> JKnight
--
David Strauss
| da...@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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