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Date: Tue, 27 Mar 2012 10:51:24 +0200
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 <CALk=J5_USyq8pCaqoZj+Yi4Qb2-vshpH=u9KHwgtTUhwFB9neA@mail.gmail.com>
Subject: Re: Schema advice/help
From: Maciej Miklas <mac.miklas@googlemail.com>
To: user@cassandra.apache.org
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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 ?
>>
>
>

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multiget would require Order Preserving Partitioner, and this can lead to u=
nbalanced ring and hot spots.<br><br>Maybe you can use secondary index on &=
quot;itemtype&quot; - is must have small cardinality: <a href=3D"http://pkg=
hosh.wordpress.com/2011/03/02/cassandra-secondary-index-patterns/">http://p=
kghosh.wordpress.com/2011/03/02/cassandra-secondary-index-patterns/</a><br>
<br><br><br><div class=3D"gmail_quote">On Tue, Mar 27, 2012 at 10:10 AM, Gu=
y Incognito <span dir=3D"ltr">&lt;<a href=3D"mailto:dnd1066@gmail.com">dnd1=
066@gmail.com</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" st=
yle=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
without the ability to do disjoint column slices, i would probably use 5 di=
fferent rows.<br>
<br>
userId:itemType -&gt; activityId<br>
<br>
then it&#39;s a multiget slice of 10 items from each of your 5 rows.<div><d=
iv></div><div class=3D"h5"><br>
<br>
On 26/03/2012 22:16, Ertio Lew wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
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 =3D50).<br>
<br>
I am wanting to store these activities in a single row for each user so tha=
t they can be retrieved in single row query, since I want to read all the l=
ast 10 activities on each item.. I am thinking of creating composite names =
appending &quot;itemtype&quot; : &quot;activityId&quot;(activityId is just =
timestamp value) but then, I don&#39;t see about how to read the last 10 ac=
tivities from all itemtypes.<br>

<br>
Any ideas about schema to do this better way ?<br>
</blockquote>
<br>
</div></div></blockquote></div><br>

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