Row count of a column family in Cassandra

Question

Is there a way to get a row count (key count) of a single column family in Cassandra? get_count can only be used to get the column count.

For instance, if I have a column family containing users and wanted to get the number of users. How could I do it? Each user is it's own row.

Answer 1

I have been getting the counts like this after I convert the data into a hash in PHP.

Answer 2

If you are using an order-preserving partitioner, you can do this with get_range_slice or get_key_range.

If you are not, you will need to store your user ids in a special row.

Answer 3

Did you find any solution on how to count column family without using hash in php?

Answer 4

I'm new to Cassandra, but I have messed around a lot with Google's App Engine. If no other solution presents itself, you may consider keeping a separate counter in a platform that supports atomic increment operations like memcached. I know that Cassandra is working on atomic counter increment/decrement functionality, but it's not yet ready for prime time.

I can only post one hyperlink because I'm new, so for progress on counter support see the link in my comment below.

Note that this thread suggests ZooKeeper, memcached, and redis as possible solutions. My personal preference would be memcached.

http://www.mail-archive.com/[email protected]/msg03965.html