I should have been more clear. What I meant was that its about the same amount of work for the cluster to do a “select count(l)” as it is to do a “select l” (unlike in the RDBMS world, where count(l) can use the primary key index). The reason why is the coordinator has to retrieve all the rows from all the nodes and count them. The only thing you’re saving is that the rows don’t have to be sent to the client.
I heard from another Cassandra user that they found “select l" to be faster than "select count(l)”. I don’t know why that would be, but I’ve seen stranger things. Robert On Apr 22, 2015, at 7:49 AM, Mich Talebzadeh <m...@peridale.co.uk<mailto:m...@peridale.co.uk>> wrote: Thanks Robert, In RDBMS select count(1) basically returns the rows. 1> select count(1) from t 2> go ----------- 300000 (1 row affected) Is count(1) fundamentally different in Cassandra? Does count(1) means return (in my case) 1 three hundred thousand time? Cheers, Mich Talebzadeh http://talebzadehmich.wordpress.com<http://talebzadehmich.wordpress.com/> Author of the books "A Practitioner’s Guide to Upgrading to Sybase ASE 15", ISBN 978-0-9563693-0-7. co-author "Sybase Transact SQL Guidelines Best Practices", ISBN 978-0-9759693-0-4 Publications due shortly: Creating in-memory Data Grid for Trading Systems with Oracle TimesTen and Coherence Cache Oracle and Sybase, Concepts and Contrasts, ISBN: 978-0-9563693-1-4, volume one out shortly NOTE: The information in this email is proprietary and confidential. This message is for the designated recipient only, if you are not the intended recipient, you should destroy it immediately. Any information in this message shall not be understood as given or endorsed by Peridale Ltd, its subsidiaries or their employees, unless expressly so stated. It is the responsibility of the recipient to ensure that this email is virus free, therefore neither Peridale Ltd, its subsidiaries nor their employees accept any responsibility. From: Robert Wille [mailto:rwi...@fold3.com] Sent: 22 April 2015 14:44 To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Re: OperationTimedOut in selerct count statement in cqlsh Keep in mind that "select count(l)" and "select l" amount to essentially the same thing. On Apr 22, 2015, at 3:41 AM, Tommy Stendahl <tommy.stend...@ericsson.com<mailto:tommy.stend...@ericsson.com>> wrote: Hi, Checkout CASSANDRA-8899, my guess is that you have to increase the timeout in cqlsh. /Tommy On 2015-04-22 11:15, Mich Talebzadeh wrote: Hi, I have a table of 300,000 rows. When I try to do a simple cqlsh:ase> select count(1) from t; OperationTimedOut: errors={}, last_host=127.0.0.1 Appreciate any feedback Thanks, Mich NOTE: The information in this email is proprietary and confidential. This message is for the designated recipient only, if you are not the intended recipient, you should destroy it immediately. Any information in this message shall not be understood as given or endorsed by Peridale Ltd, its subsidiaries or their employees, unless expressly so stated. It is the responsibility of the recipient to ensure that this email is virus free, therefore neither Peridale Ltd, its subsidiaries nor their employees accept any responsibility.
