HyperDB is a very advanced database class that replaces a few of the WordPress built-in database functions. The main differences are:
- HyperDB can be connect to an arbitrary number of database servers,
- HyperDB inspects each query to determine the appropriate database.
It supports:
- Read and write servers (replication)
- Configurable priority for reading and writing
- Local and remote datacenters
- Private and public networks
- Different tables on different databases/hosts
- Smart post-write master reads
- Failover for downed host
- Advanced statistics for profiling
It is based on the code currently used in production on WordPress.com with many MySQL servers spanning multiple datacenters.
This is a fork of the HyperDB plugin written by Automattic, which can be found at https://en-gb.wordpress.org/plugins/hyperdb/