Method, media, and systems for compressing objects, comprising: receiving a request to write a first object including a first key and a first value, wherein the first object is of a given type; receiving a request to write a second object including a second key and a second value, wherein the second object is of the given type; classifying the first object to a compression dictionary according to at least one rule based on a value of the first object and/or the key of the first object; classifying the second object to the compression dictionary according to at least one rule based on a value of the second object and/or the key of the second object; and compressing the first object and the second object based on the compression dictionary.