Question

I have a situation where I could really benefit from having system like memcached, but with the ability to store (per each key) sorted list of elements, and modifying the list by addition of values.

For example:

something.add_to_sorted_list( 'topics_list_sorted_by_title', 1234, 'some_title')
something.add_to_sorted_list( 'topics_list_sorted_by_title', 5436, 'zzz')
something.add_to_sorted_list( 'topics_list_sorted_by_title', 5623, 'aaa')

Which I then could use like this:

something.get_list_size( 'topics_list_sorted_by_title' )
// returns 3
something.get_list_elements( 'topics_list_sorted_by_title', 1, 10 )
// returns: 5623, 1234, 5436

Required system would allow me to easily get items count in every array, and fetch any number of values from the array, with the assumption that the values are sorted using attached value.

I hope that the description is clear. And the question is relatively simple: is there any such system?

Answer 1

Redis supports both lists and sets. You can disable disk saving and use it like Memcached instead of going for MongoDB which would save data to disk.