> - 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.kr...@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:andys...@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? > > > > _______________________________________________ > > This message may contain information that is confidential or privileged. If > you are not an intended recipient of this message, please delete it and any > attachments, and notify the sender that you have received it in error. Unless > specifically stated in the message or otherwise indicated, you may not > duplicate, redistribute or forward this message or any portion thereof, > including any attachments, by any means to any other person, including any > retail investor or customer. This message is not a recommendation, advice, > offer or solicitation, to buy/sell any product or service, and is not an > official confirmation of any transaction. Any opinions presented are solely > those of the author and do not necessarily represent those of Barclays. This > message is subject to terms available at: www.barclays.com/emaildisclaimer > and, if received from Barclays' Sales or Trading desk, the terms available > at: www.barclays.com/salesandtradingdisclaimer/. By messaging with Barclays > you consent to the foregoing. Barclays Bank PLC is a company registered in > England (number 1026167) with its registered office at 1 Churchill Place, > London, E14 5HP. This email may relate to or be sent from other members of > the Barclays group. > > _______________________________________________ >
