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From Maciej Miklas <mac.mik...@gmail.com>
Subject Re: CQL 3 and wide rows
Date Mon, 19 May 2014 20:17:32 GMT
Hallo Jack,

You have given a perfect example for wide row.  Each reading from sensor creates new column
within a row. It was also possible with Hector/CLI to have millions of columns within a single
row. According to this page http://wiki.apache.org/cassandra/CassandraLimitations single row
can have 2 billions columns.

How does this relate to CQL 3 and tables? 

I still do not understand it because:
- it looks like driver loads all column names into memory - it looks to me that the 2 billions
limitation from CLI is not valid anymore
- Map and Set values do not support iterator 


Regards,
Maciej


On 19 May 2014, at 17:31, Jack Krupansky <jack@basetechnology.com> wrote:

> You might want to review this blog post on supporting dynamic columns in CQL3, which
points out that “the way to model dynamic cells in CQL is with a compound primary key.”
>  
> See:
> http://www.datastax.com/dev/blog/does-cql-support-dynamic-columns-wide-rows
>  
> -- Jack Krupansky
>  
> From: Maciej Miklas
> Sent: Monday, May 19, 2014 11:20 AM
> To: user@cassandra.apache.org
> Subject: CQL 3 and wide rows
>  
> Hi *,
>  
> I’ve checked DataStax driver code for CQL 3, and it looks like the column names for
particular table are fully loaded into memory, it this true?
>  
> Cassandra should support wide rows, meaning tables with millions of columns. Knowing
that, I would expect kind of iterator for column names. Am I missing something here?
>  
>  
> Regards,
> Maciej Miklas


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