| Feature | DynamoDB | MongoDB | Casandra |
|---|---|---|---|
| DB Type | Key-Value & Document DB Store (with well-defined query pattern). | Document DB Store - Maximum data model flexibility & nested data. | Wide-Column DB Store |
| Writing Scalability | 🚀 Very high and efficient | Write scalability is limited in MongoDB. | 🚀 Writing scalability in Cassandra is very high and efficient (due to append-only nature). |
| Read Performance | Highly efficient due to fast key lookup | Good read performance, with eventual consistency. | 🚀 Read performance is highly efficient in Cassandra as it takes O(1) time. |
| Data Format | Key-Value (JSON) | MongoDB supports both JSON and BSON data formats. | Cassandra only supports JSON data format. |
| Sharding support | 👍 Yes | 👍 Yes | 👍 Yes |
| Replication Method | Single-Leader Replication | Single-Leader replication | Leaderless replication |
| ACID Support | 👍 Yes | 👍 MongoDB provides Multi-document ACID transactions with snapshot isolation. | ❌ Cassandra does not provides ACID transactions but can be tuned to support ACID properties. |
| Secondary Indexes | 👍 Yes | 👍 Yes | ❌ Cassandra has only cursory support for secondary indexes. |
| Used by | Twillo, Mcafee, others etc. | 👍 Famous companies like Adobe, Amadeus, Lyft, ViaVarejo, Craftbase, etc uses MongoDB. | Famous companies like Hulu, Instagram, Intuit, Netflix, Reddit, etc uses Cassandra. |