Advanced CRUD operations
The basic CRUD operations we've just seen are fairly straightforward and mimic what you'd expect to see in a relational system. As a key/value store, however, Couchbase provides a handful of additional, unique CRUD operations.
Temporary keys
As a descendant of the in-memory-only Memcached, Couchbase supports a set of operations you might not expect to see in a persistent store. Specifically, each of the CRUD methods outlined allows an expiry date to be provided. When set, this "time to live" option will be used to trigger the removal of a key by the server.
It is common in relational systems to have tables with expiration date columns. In this case, the expiry date is likely a flag to be used by a scheduled task that cleans old records. Couchbase Server allows you to achieve this very functionality without the need for a scheduled task or additional properties in the stored value.
To create a key with an expiry date, you can use either the set or add operation. You'll...
