1 Around 10% of men is affected by pearly penile papules.  After masturbation or sexual intercourse hard swelling might appear near the foreskin, in the shaft of the head of the penis. This swelling is called lymphocele, and is caused by temporary blockage of the lymphatic channels at the area described.
A key-value store, or key-value database, is a data storage paradigm designed for storing, retrieving, and managing associative arrays, a data structure more commonly known today as a dictionary or hash. Dictionaries contain a collection of objects, or records, which in turn have many different fields within them, each containing data.
Graph stores are used to store information about networks of data, such as social connections. Graph stores include Neo4J and Giraph. Key-value stores are the simplest NoSQL databases. Every single item in the database is stored as an attribute name (or 'key'), together with its value.