In Apache Cassandra versions 0.4 to 2.2, SSTable data was structured by row key. A row key kept a map of columns underneath it with their values. These columns were sorted by their column key. If you consider the key/value map structure from Java, it's easy to think of it as a map of a map.
As an example, consider the following CQL query from the previous chapter. Recall that it retrieves video game high-score data for a player named Connor:
cassdba@cqlsh:packt> SELECT * FROM hi_scores WHERE name='Connor'; name | game | score--------+-------------+-------- Connor | Frogger | 4220 Connor | Joust | 48850 Connor | Monkey Kong | 15800 Connor | Pacman | 182330(4 rows)
This CQL query and result set make ...
