MariaDB strives to be the logical choice for database professionals looking for a robust, scalable, and reliable SQL server. To accomplish this, the MariaDB Foundation work closely and cooperatively with the larger community of users and developers in the true spirit of free and open source software, and release software in a manner that balances predictability with reliability.
Google Spanner is a Google Cloud-based database system that is ACID compliant, horizontally scalable, and global. Spanner is the database that underpins much of Google’s own data collection, and it has been designed to offer the consistency of a relational database along with the freedom of a non-relational one.