{ "id": "apache-cassandra-vs-amazon-dynamodb", "ids": [ "apache-cassandra", "amazon-dynamodb" ], "title": "Apache Cassandra vs Amazon DynamoDB: partitions, operations and cost", "heading": "Apache Cassandra vs Amazon DynamoDB", "kicker": "Database software comparison", "deck": "Compare Cassandra and DynamoDB for partition-oriented application access, data modelling, operating responsibilities and managed-service billing.", "description": "Compare Cassandra and DynamoDB for partition-oriented application access, data modelling, operating responsibilities and managed-service billing.", "answerHeading": "Which database approach fits the workload?", "answer": "Consider Cassandra when its wide-column model, CQL and distributed deployment fit the workload and the team can own or contract the operating service. Consider DynamoDB when its key-value and document access patterns fit an AWS-managed service. Both require deliberate key and index design. Cassandra project software and a managed DynamoDB deployment are different buying scopes, so include the operating work before comparing cost.", "checkedAt": "2026-10-15", "researchTag": "Data model, application fit and operating scope", "researchLimit": "Official product, pricing and technical documentation reviewed. These are proposed evaluation briefs, not completed migrations, performance benchmarks or reliability measurements.", "datasetDescription": "Seven application and buying differences, four proposed database exercises and four acceptance checks for Apache Cassandra vs Amazon DynamoDB.", "type": "workflow-buying", "rows": [ [ "Product", "Apache distributed database software", "AWS-managed database service" ], [ "Primary model", "Partitioned wide-column tables and CQL", "Key-value and document items accessed through service APIs" ], [ "Access design", "Partition and clustering design around intended queries", "Primary keys and secondary indexes around intended access" ], [ "Operations", "Assign cluster maintenance, repair, upgrade and recovery", "Assign application modelling and service configuration; AWS manages service infrastructure" ], [ "Replication", "Specify topology, replication and consistency choices", "Specify the required regional and global-table configuration" ], [ "Free boundary", "Free project software; infrastructure and services separate", "Limited provisioned-capacity allowance differs from on-demand usage" ], [ "Cost model", "Infrastructure, replicas, storage, network, support and staff", "Capacity or requests, indexes, storage, replication and optional services" ] ], "scenarios": [ { "name": "A keyed request", "question": "Can the application retrieve the expected account history?", "left": "Design the partition and clustering approach for the request.", "right": "Design the key and index approach for the same request.", "note": "Use realistic account activity and a deliberately uneven access pattern." }, { "name": "A new access pattern", "question": "What work is needed to add a second application query?", "left": "Document any table, index or pipeline change.", "right": "Document any index, item-shape or pipeline change.", "note": "A SQL-like query language does not establish unrestricted relational access." }, { "name": "A retry", "question": "How does the application handle an uncertain write outcome?", "left": "Exercise the selected consistency and application retry logic.", "right": "Exercise the service API and application retry logic.", "note": "Define an application-level operation identity and reconcile duplicates or conflicts." }, { "name": "A larger deployment", "question": "Who owns the change and what is billed?", "left": "Plan the cluster or managed-provider change and operating tasks.", "right": "Model the chosen capacity mode and additional service usage.", "note": "Use the same data, replicas, region needs and workload assumptions." } ], "exampleTable": { "caption": "Proposed acceptance checks for an authorised evaluation; no measured product result is implied.", "headers": [ "Requirement", "Proposed exercise", "Accept when" ], "rows": [ [ "Access pattern", "Implement account history and one alternate lookup", "Keys, indexes and returned order match the requirement" ], [ "Model change", "Add a required access pattern to the sample", "Migration and ongoing maintenance are documented" ], [ "Retry outcome", "Repeat an operation after a simulated uncertain response", "The application reconciles the intended business result" ], [ "Full cost", "Model a normal and defined growth workload", "Operating responsibilities and all major cost units are listed" ] ] }, "sections": [ { "id": "partition-design", "title": "Make the access pattern explicit", "navLabel": "Partition design", "paragraphs": [ "List the application’s important reads and writes, including ordering, consistency and response requirements. Model uneven keys as well as average activity; a uniform sample can conceal the part of the workload that needs the most design.", "CQL uses familiar-looking syntax, but Cassandra is not a relational join engine. DynamoDB’s service API likewise does not remove the need to plan keys, indexes and application behaviour." ] }, { "id": "service-boundary", "title": "Price the service boundary honestly", "navLabel": "Service costs", "paragraphs": [ "A Cassandra software download does not include servers, monitoring, repair, recovery or a support team. A third-party managed Cassandra service must be assessed under its own contract and compatibility scope.", "For DynamoDB, select provisioned or on-demand capacity and include storage, indexes and required regional or recovery features. Keep the documented provisioned free allowance separate from on-demand usage or temporary credits." ] } ], "faqs": [ { "question": "Does CQL mean Cassandra works like a relational SQL database?", "answer": "No. Cassandra uses a partitioned wide-column model. Its architecture does not provide general distributed joins or unrestricted cross-partition transactions." }, { "question": "Does DynamoDB’s free allowance cover all on-demand requests?", "answer": "No. The documented ongoing allowance is tied to provisioned capacity and other conditions. Check the actual capacity mode and account." }, { "question": "Is this a throughput benchmark?", "answer": "No. The exercises describe what to evaluate in a representative deployment; no comparative throughput or reliability measurements were performed." } ], "sources": [ { "url": "https://cassandra.apache.org/doc/latest/cassandra/architecture/overview.html", "facts": "Partitioned wide-column model, CQL, replication and operational responsibilities; no general distributed joins." }, { "url": "https://cassandra.apache.org/_/index.html", "facts": "Apache open-source database project and deployment context." }, { "url": "https://aws.amazon.com/dynamodb/", "facts": "AWS-managed NoSQL database for key-value and document application data." }, { "url": "https://aws.amazon.com/dynamodb/pricing/", "facts": "Provisioned and on-demand capacity models; free allowance and additional replication, storage or recovery costs." } ], "relatedLinks": [ { "path": "/categories/database-software/", "title": "Explore database software" }, { "path": "/guides/database-models-search-documents-graphs-analytics/", "title": "Choose a database model for search, documents, graphs and analytics" }, { "path": "/guides/database-managed-vs-self-hosted/", "title": "Compare managed and self-hosted database responsibilities" } ], "downloads": [ { "path": "/downloads/apache-cassandra-vs-amazon-dynamodb-evaluation.csv", "title": "Download the database evaluation checklist (CSV)", "description": "Four proposed checks with blank evidence and owner fields. Record the exact version, edition, region, deployment and workload used." } ] }