In a typical web application, caching is used to store the result of an expensive operation for later use to reduce the load on the database or external services. However, sometimes, we need to delete these cached items - maybe the data has changed, or we are no longer in need of that particular piece of information. This is where deleting keys from Memcached comes in Ruby applications.
Dalli gem is commonly used in Ruby applications for interfacing with a Memcached server. Here's how you might delete a key using Dalli:
In this example, we first set up a connection to the Memcached server with
Dalli::Client.new. Then we set a value for a key using
dc.set, and then we delete that key-value pair from the cache using
What happens if I try to delete a non-existent key in Memcached?
Memcached will simply return a "NOT_FOUND" response, and no error will occur.
Can I recover a deleted key in Memcached?
No, once a key is deleted, it can't be recovered. Memcached isn't meant to be a persistent data store.
Can I delete multiple keys at once in Memcached?
No, Memcached does not support multi-delete operations. You have to delete each key individually.