Hi, this is true for CQL2, it doesn't work for CQL3:
cqlsh:c4> SELECT id from some_table WHERE indexed_column='test'; ... cqlsh:c4> SELECT KEY from some_table WHERE indexed_column='test'; Bad Request: Undefined name key in selection clause Perhaps you meant to use CQL 2? Try using the -2 option when starting cqlsh. regards, Ondřej Černoš On Thu, Apr 25, 2013 at 10:32 AM, <moshe.kr...@barclays.com> wrote: > IMHO: user_name is not a column, it is the row key. Therefore, according > to http://thelastpickle.com/2011/07/04/Cassandra-Query-Plans/ , the row > does not contain a relevant column index, which causes the iterator to read > each column (including value) of each row.**** > > ** ** > > I believe that instead of referring to user_name as if it were a column, > you need to refer to it via the reserved word “KEY”, e.g.:**** > > ** ** > > Select KEY from users where status = 2; **** > > ** ** > > Always glad to share a theory with a friend….**** > > ** ** > > ** ** > > *From:* Tamar Rosen [mailto:ta...@correlor.com] > *Sent:* Thursday, April 25, 2013 11:04 AM > *To:* user@cassandra.apache.org > *Subject:* Secondary Index on table with a lot of data crashes Cassandra** > ** > > ** ** > > Hi,**** > > ** ** > > We have a case of a reproducible crash, probably due to out of memory, but > I don't understand why. **** > > ** ** > > The installation is currently single node. **** > > ** ** > > We have a column family with approx 50000 rows. **** > > ** ** > > In cql, the CF definition is:**** > > ** ** > > ** ** > > CREATE TABLE users (**** > > user_name text PRIMARY KEY,**** > > big_json text,**** > > status int**** > > );**** > > ** ** > > Each big_json can have 500K or more of data.**** > > ** ** > > There is also a secondary index on the status column. **** > > Status can have various values, over 90% of all rows have status = 2. **** > > ** ** > > ** ** > > Calling:**** > > ** ** > > Select user_name from users limit 80000;**** > > ** ** > > Is pretty fast**** > > ** ** > > ** ** > > ** ** > > Calling:**** > > ** ** > > Select user_name from users where status = 1; **** > > is slower, even though much less data is returned.**** > > ** ** > > Calling:**** > > ** ** > > Select user_name from users where status = 2; **** > > ** ** > > Always crashes.**** > > ** ** > > ** ** > > What are we doing wrong? Can it be that Cassandra is actually trying to read > all the CF data rather than just the keys! (actually, it doesn't need to go > to the users CF at all - all the data it needs is in the index CF)**** > > ** ** > > ** ** > > Also, in the code I am doing the same using Astyanax index query with > pagination, and the behavior is the same. **** > > > > **** > > Please help me:**** > > ** ** > > 1. solve the immediate issue**** > > ** ** > > 2. understand if there is something in this use case which indicates that we > are not using Cassandra the way it is meant. **** > > ** ** > > > > **** > > Thanks,**** > > ** ** > > > > **** > > Tamar Rosen**** > > ** ** > > Correlor.com**** > > ** ** > > > > **** > > ** ** > > _______________________________________________ > > 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. > > _______________________________________________ >
