Cassandra vs RDBMS
| Cassandra | RDBMS |
| Deals with unstructured data. | Deals with structured data. |
| Flexible schema. | Fixed schema. |
| Table can be understood as a list of “nested key-value pairs”, i.e., Row x Column Key x Column value) | Table can be understood as an array of arrays, i.e., Row x Column. |
| Keyspace is the outermost container containing data of an application. | Database is the outermost container containing data of an application. |
| Tables or column families are the entity of a keyspace. | Tables are the entities of a database. |
| Row is a unit of replication. | Row is an individual record. |
| Column is a unit of storage. | Column represents the attributes of a relation. |
| Collections are used to represent relationships. | There are concept of foreign keys, joins, etc. |