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From "Hiller, Dean" <Dean.Hil...@nrel.gov>
Subject Re: Secondary Index Question
Date Wed, 21 Aug 2013 15:55:51 GMT
Sorry, I forget why.  Someone told me at the cassandra conference.  It
might be to not overload the entire cluster at once so if you have 1000
nodes and you run just 5 queries, you could take out your cluster.  (This
is why I use playorm's querying and in tons of use cases, you don't want
to query the entire clusterĊ .usually that is saved for a map/reduce type
operation).

Dean

On 8/21/13 9:10 AM, "Kanwar Sangha" <kanwar@mavenir.com> wrote:

>Thanks Dean. Any reason why it is sequential ? It is to avoid loading all
>the nodes and see if one node can return the desired results ?
>
>
>-----Original Message-----
>From: Hiller, Dean [mailto:Dean.Hiller@nrel.gov]
>Sent: 21 August 2013 07:36
>To: user@cassandra.apache.org
>Subject: Re: Secondary Index Question
>
>Yup, there are other types of indexing like that in PlayOrm which do it
>differently so all nodes are not hit so it works better for instance if
>you are partitioning your data and you query into just a single partition
>so it doesn't put load on all the nodes.  (of course, you have to have a
>partition strategy to partition by say month with key being the timestamp
>of begin of month or maybe you partition by account as you only query
>into accounts).
>
>It is feasible to roll your own as well.  (though you do need to worry
>about eventual consistency here when rolling your own)
>
>Later,
>Dean
>
>From: Kanwar Sangha <kanwar@mavenir.com<mailto:kanwar@mavenir.com>>
>Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
><user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
>Date: Tuesday, August 20, 2013 6:57 PM
>To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>"
><user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
>Subject: Secondary Index Question
>
>Hi - I was reading some blogs on implementation of secondary indexes in
>Cassandra and they say that "the read requests are sent sequentially to
>all the nodes" ?
>
>So if I have a query to fetch ALL records with the secondary index
>filter, will the co-ordinator node send the requests to nodes one by one ?
>
>Thanks,
>Kanwar
>


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