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Stores data persistently, as well as in memory. It allows data to be automatically replicated for high availability, using the Database Change Protocol (DCP); and dynamically scaled across multiple clusters, by means of Cross Datacenter Replication (XDCR).

Ephemeral buckets are an alternative to Couchbase buckets, to be used whenever persistence is not required: for example, when repeated disk-access involves too much overhead. This allows highly consistent in-memory performance, without disk-based fluctuations. It also allows faster node rebalances and restarts.

Memcached buckets are designed to be used alongside other database platforms, such as ones employing relational database technology. By caching frequently-used data, Memcached buckets reduce the number of queries a database-server must perform. Each Memcached bucket provides a directly addressable, distributed, in-memory key-value cache.