I use one of two ways to achieve that: 1. run a map reduce. Pig is really helpful in these cases. Make sure you run your MR using Hadoop task tracker on your nodes - or your performance will take a hit. 2. dump all keys using sstablekeys script from relevant files on all machines and count unique values. I do that using "sort -n keys.txt |uniq >> unique_keys.txt"
Dumping all keys is much faster but less elegant and can be more annoying if you want do that from your application. Hope that do the trick for you. -Orr -----Original Message----- From: Joshua Partogi [mailto:joshua.j...@gmail.com] Sent: Monday, March 28, 2011 2:39 PM To: user@cassandra.apache.org Subject: Re: newbie question: how do I know the total number of rows of a cf? Not all NoSQL is like that. Or perhaps the term NoSQL has became vague these days. On Mon, Mar 28, 2011 at 6:16 PM, Stephen Connolly <stephen.alan.conno...@gmail.com> wrote: > iterate. > > otherwise if that will be too slow and you will do it often, the nosql way > is to create a separate column family updated with each row add/delete to > hold the answer for you. > > - Stephen > > --- > Sent from my Android phone, so random spelling mistakes, random nonsense > words and other nonsense are a direct result of using swype to type on the > screen > > On 28 Mar 2011 07:40, "Sheng Chen" <chensheng2...@gmail.com> wrote: >> Hi all, >> I want to know how many records I am holding in Cassandra, just like >> count(*) in sql. >> What can I do ? Thank you. >> >> Sheng > -- http://twitter.com/jpartogi
