SurrealDB

vs

HarperDB

Supabase is a free and open-source self-hosted and SaaS provided alternative to Firebase. With Supabase you can add a realtime REST API to a PostgreSQL without writing a single line of code.

Fauna is the data API for client-serverless applications. It provides web-native GraphQL interface, with support for custom business logic and integration with the serverless ecosystem. Fauna transforms the traditional DBMS into a Data API that gives you all of the capabilities of traditional database, without sacrificing flexibility, scale, and performance. By utilizing a globally-distributed storage and compute fabric, Fauna-powered applications are delivered to end-users fast and reliably on modern security infrastructure.

EdgeDB is a database designed on top of Postgres with the goal of eliminating some of the shortcommings of relation and NoSQL databases.  At first glance, EdgeDB looks like a regular object relational mapper (ORM), however it's far more than that, It's a full-fledged database with a formally-defined query language, a migrations system, a suite of client libraries in different languages, a command line tool, and a soon comming cloud hosting platform. The goal of EdgeDB has been to rethink every aspect of how developers model, migrate, manage, and query their database.

Amazon DynamoDB is a key-value and document database that delivers single-digit millisecond performance at any scale. The database is fully managed, multiregion, multimaster, and durable with built-in security, backup and restore, and in-memory caching for enterprise-scale applications. Amazon DynamoDB is part of Amazon Web Services and integrates well with other cloud-based AWS products.

Azure Cosmos DB is a non-relational NoSQL database trusted by leading enterprises globally. With Azure Cosmos DB you can run No-ETL analytics over real-time operational data and run near-real time analytics and AI on the operational data within your NoSQL database, to reduce time to insight.

TimescaleDB is a leading open-source relational database for time-series data. The database is provided as fully managed or self‑hosted software, giving the power of choice back to developers and organizations. Timescale gives you all the reliability and flexibility of PostgreSQL. It allows you to use regular SQL to construct queries to better understand your products and your users. While achieve 10-100x faster queries than PostgreSQL, InfluxDB, and MongoDB with native optimizations for time-series.