Baidu Tera vs SWC-DB

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.

SWC-DB is a self-hosted Super Wide Column Database that the maker describes as a key-value, wide-column NoSQL and time-series database. It supports SQL, but SQL has no joins, and the system is designed for very large data volumes. Its data model uses cell keys made from lists of fractions with timestamps, with numerous columns rather than tables or namespaces. Data can have automatic or user-defined versions, ordered ascending or descending, with a configurable maximum retained. The maker describes ACID concepts for a single data entry; writes across multiple entries are not atomic as a group. Communications can use SSL, but transaction security also depends on the configured filesystem and clients supporting a secure layer. User-concept access controls are unsupported. A cluster utility can deploy, start and stop distributed clusters. Downloads include tar.xz and Debian packages, with Arch Linux AUR packages also described. SWC-DB is free under GPLv3; commercial-purpose licensing inquiries are invited for uses limited by that license.