Azure Cosmos DB for NoSQL vs Baidu Tera

Azure Cosmos DB for NoSQL is a fully managed cloud database built around schema-agnostic JSON documents and SQL-like querying. It supports global data distribution, multi-region writes, and automatic failover, with configurable consistency controls and transactions. Search includes vector and hybrid similarity capabilities for workloads such as retrieval-augmented generation and AI agents. Throughput can use standard provisioned, autoscale provisioned, or serverless models. The service lists SDKs for.NET, Java, JavaScript/Node.js, Python, Go, and Rust. Its change feed can support event-driven architectures and streaming pipelines using Azure Functions and Spark; no-ETL analytical workflows are available through Azure Synapse Link or Fabric mirroring. Microsoft states that NoSQL data has service-level agreements including less than 10 millisecond read and write latency and 99.999 percent availability. A free tier includes 1,000 RU/s and 25 GB of storage for one account per Azure subscription, and a 30-day trial is listed. The Azure Cosmos DB emulator provides a no-cost local development environment for Windows or Linux. The pricing page notes that the selected compute pricing model and API cannot be changed after selection.

Baidu Tera is a free, self-hosted distributed NoSQL database for real-time applications. It stores sparse, multidimensional tables indexed by row key, column key and timestamp, with the project describing scale to petabytes across thousands of commodity servers. Tera supports strict consistency, MVCC, automatic failover, online schema changes and snapshots. Configurable automatic sharding can use ranged or hashed strategies, with linear and modular scalability. Storage options include RAMDISK, SSD and disk tables, plus tiered and block caches and Bloom Filters for real-time queries. Applications can connect through C++, Java, Python and REST APIs. Its architecture includes an SDK, master and tablet servers using an enhanced LevelDB engine. Deployment can use raw machines or Docker, with pseudo-distributed operation on one host. The repository lists BSD-3-Clause and Apache-2.0 licenses.