Now that you've got an in-depth understanding of the feature set that Cassandra offers, it's time to figure out which features are most important to you and which database is the best fit. The following table lists a handful of commonly used databases and key features that they do or don't have:
| Feature | Cassandra | PostgreSQL | MongoDB | Redis | Riak |
| Structured records | Yes | Yes | Yes | Limited | No |
| Secondary indexes | Yes | Yes | Yes | No | Yes |
| Discretely writable collections | Yes | Yes | Yes | Yes | No |
| Relational joins | No | Yes | No | No | No |
| Built-in MapReduce | No | No | Yes | No | Yes |
| Fast result ordering | Yes | Yes | Yes | Yes | No |
| Immediate consistency | Configurable at query level | Yes | Yes | Yes | Configurable at cluster level |
| Transparent sharding ... |
