Cassandra Vs RDBMS
The following table specifying the main differences between Cassandra and RDBMS:
| Cassandra | RDBMS |
|---|---|
| Cassandra is used to deal with unstructured data. | RDBMS is used to deal with structured data. |
| Cassandra has flexible schema. | RDBMS has fixed schema. |
| In Cassandra, a table is a list of "nested key-value pairs". (Row x Column Key x Column value) | In RDBMS, a table is an array of arrays. (Row x Column) |
| In Cassandra, keyspace is the outermost container which contains data corresponding to an application. | In RDBMS, database is the outermost container which contains data corresponding to an application. |
| In Cassandra, tables or column families are the entity of a keyspace. | In RDBMS, tables are the entities of a database. |
| In Cassandra, row is a unit of replication. | In RDBMS, row is an individual record. |
| In Cassandra, column is a unit of storage. | In RDBMS, column represents the attributes of a relation. |
| In Cassandra, relationships are represented using collections. | In RDBMS, there are concept of foreign keys, joins etc. |
