RE: CQL get unique row keys ?
Thanks, worked a treat ! Andy From: DuyHai Doan Sent: 15 February 2014 18:51 To: user@cassandra.apache.org Subject: Re: CQL get unique row keys ? Hello Andy Since C* 2.0.1 it is possible to list all distinct partition keys (not clustering keys) with: SELECT DISTINCT pk FROM More info on the feature here: https://issues.apache.org/jira/browse/CASSANDRA-4536 This query is quite efficient because the key cache is used most of the time. Regards Duy Hai DOAN On Sat, Feb 15, 2014 at 6:05 PM, Andrew Cobley mailto:a.e.cob...@dundee.ac.uk>> wrote: I may be missing something here, but is there a way in cql to get all unique row keys in a column family(table) ? I've created a table like this: CREATE TABLE totp ( artist varchar, track varchar, appearance_type varchar, PRIMARY KEY ((artist),track) ) WITH CLUSTERING ORDER BY (track asc); and populated it with data. As you can imagine, each artist can have multiple tracks . Doing: Select * from totp; will produce something like (with more artists of course) The Tony Rich Project | Nobody Knows | P/A Telly Savalas | If | PROMO Alice Cooper | Elected |DISC Alice Cooper | Hello Hooray | PROMO Alice Cooper | Hey Stupid | Promo Alice Cooper | Lost In America | P/A Alice Cooper | No More Mr.Nice Guy |DISC Alice Cooper | Poison | Promo Alice Cooper | School's Out | P/A V/T Alice Cooper | Schools Out | P/A Alice Cooper | Teenage Lament '74 |DISC Blackstreet Feat Dr.Dre | No Diggity | P/A Nena | 99 Luftballons | Promo Nena | 99 Red Balloons | P/A and Select artist from totp; would produce: The Tony Rich Project Telly Savalas Alice Cooper Alice Cooper Alice Cooper Alice Cooper Alice Cooper Alice Cooper Alice Cooper Alice Cooper Alice Cooper Blackstreet Feat Dr.Dre Nena Nena But of course what I really want is just the row keys The Tony Rich Project Telly Savalas Alice Cooper Blackstreet Feat Dr.Dre Nena Any idea if I can do this in CQL ? Andy The University of Dundee is a registered Scottish Charity, No: SC015096 The University of Dundee is a registered Scottish Charity, No: SC015096
Re: CQL get unique row keys ?
Hello Andy Since C* 2.0.1 it is possible to list all distinct partition keys (not clustering keys) with: SELECT DISTINCT pk FROM More info on the feature here: https://issues.apache.org/jira/browse/CASSANDRA-4536 This query is quite efficient because the key cache is used most of the time. Regards Duy Hai DOAN On Sat, Feb 15, 2014 at 6:05 PM, Andrew Cobley wrote: > I may be missing something here, but is there a way in cql to get all > unique row keys in a column family(table) ? > > I've created a table like this: > > CREATE TABLE totp ( > artist varchar, > track varchar, > appearance_type varchar, > PRIMARY KEY ((artist),track) > ) WITH CLUSTERING ORDER BY (track asc); > > and populated it with data. As you can imagine, each artist can have > multiple tracks . Doing: > > Select * from totp; will produce something like (with more artists of > course) > > *The Tony Rich Project* | > *Nobody > Knows* | *P/A* > *Telly Savalas* | > *If* | *PROMO* > *Alice Cooper* | > *Elected* |*DISC* > *Alice Cooper* | > *Hello > Hooray* | *PROMO* > *Alice Cooper* | > *Hey Stupid* | *Promo* > *Alice Cooper* | *Lost > In America* | *P/A* > *Alice Cooper* | *No > More Mr.Nice Guy* |*DISC* > *Alice Cooper* | > *Poison* | *Promo* > *Alice Cooper* | > *School's > Out* | *P/A V/T* > *Alice Cooper* | > *Schools Out* | *P/A* > *Alice Cooper* | *Teenage > Lament '74* |*DISC* > *Blackstreet Feat Dr.Dre* | > *No Diggity* | *P/A* > *Nena* | *99 > Luftballons* | *Promo* > *Nena* | *99 > Red Balloons* | *P/A* > *and Select artist from totp; would produce:* > > *The Tony Rich Project* > *Telly Savalas* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* > *Alice Cooper* >*Blackstreet Feat Dr.Dre* > *Nena* > *Nena* > > *But of course what I really want is just the row keys * > *The Tony Rich Project* > *Telly Savalas* > *Alice Cooper* >*Blackstreet Feat Dr.Dre* > *Nena* > > *Any idea if I can do this in CQL ?* > > *Andy* > > > The University of Dundee is a registered Scottish Charity, No: SC015096 >