1. A method comprising: identifying, for a plurality of entities and a plurality of keys stored in a data structure in a data storage unit, a plurality of entity-key associations, wherein each of the entity-key associations includes an entity and a key that are associated with each other; creating, for each of the entity-key associations, an entity-key association string by concatenating an entity identification (ID) of the entity in the entity-key association with a key ID of the key in the entity-key association, to produce a plurality of entity-key association strings; storing the entity-key association strings and a plurality of association value IDs in a plurality of shards, the association value IDs used for retrieving association values of the entity-key associations represented by the entity-key association strings; and distributing the shards to a plurality of servers in a computer network.
5. The method of claim 1 , wherein each of the entity-key associations has an association value.