A method and associated system. Entities within a first data source are identified. For each entity identified within the first data source, attributes of the entity identified within the first data source and/or relationships between the entity identified within the first data source and other entities identified within the first data source are identified. The attributes and/or relationships identified within the first data source are associated with a first entity identified within a data structure. For each entity identified within the first data source, a frequency metric characterizing the entity identified within the first data source is generated. The frequency metric is based on a frequency at which each attribute and/or relationship identified within the first data source is associated with the entity identified within the first data source. A degree of similarity between two entities of the entities is identified, by comparing the frequency metrics of the two entities.