Learning Apache Cassandra - Second Edition

Selecting more than one row

Let's say we'd like to build an administrative interface that allows employees to access data for several users on one screen. We could, of course, simply perform a query for each username specified, but Cassandra gives us a more efficient way to do this:

    SELECT * FROM "users"    WHERE "username" IN ('alice', 'bob');

This query will return two rows: one with the alice primary key and the other with the bob primary key:

Note that while this will be faster than performing two queries, it does require Cassandra to perform two seeks for the two rows, so querying for the additional row comes at some cost.