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From aaron morton <aa...@thelastpickle.com>
Subject Re: Secondary Indexes
Date Tue, 19 Mar 2013 07:20:00 GMT
> - Will that result in Cassandra creating 18 new column families,
> one for each index?
Inserts will be slower, as each insert will potentially result in 18 additional inserts. This
is just the same as a RDBMS, more indexes == more insert work. 

> - If a given column is not specified in any rows, will Cassandra
> still create an index column family?
Yes

> - The documentation says that indexes are rebuilt with every
> Cassandra restart. Why is that needed? What does the rebuild do? Does it
> read the whole column family into memory at once?
That is not correct, do you have a link for the docs ? 

As Moshe said, standard cassandra i not a great fit for faceting. Consider Solr or Data Stax
http://3.datastax.com/datastax-enterprise.php

Cheers
  
-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 17/03/2013, at 10:17 PM, moshe.kranc@barclays.com wrote:

> I do not think this is a good use case for Cassandra alone, assuming the queries can
be any combination of the 18 columns.
> I would consider using some combination of Cassandra and Solr, where Solr provides the
indexing/search, and Cassandra provides the bulk store.
>  
> From: Andy Stec [mailto:andystec@gmail.com] 
> Sent: Saturday, March 16, 2013 12:10 AM
> To: user@cassandra.apache.org
> Subject: Secondary Indexes
>  
> We need to provide search capability based on a field that is a bitmap
> combination of 18 possible values. We want to use secondary indexes to
> improve performance. One possible solution is to create a named column for
> each value and have a secondary index for each of the 18 columns.
> Questions we have are:
> 
> 
> - Will that result in Cassandra creating 18 new column families,
> one for each index?
> 
> - If a given column is not specified in any rows, will Cassandra
> still create an index column family?
> 
> - The documentation says that indexes are rebuilt with every
> Cassandra restart. Why is that needed? What does the rebuild do? Does it
> read the whole column family into memory at once?
> 
>  
>  
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