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.
A key is a sequence of one or more field IDs from the table. Up to 40 keys can be associated to a table. The first key in the list is the primary key. The primary key is always active, and the DBMS keeps the table sorted in primary key order and rejects records with duplicate values in primary key fields. Therefore, the values in the primary key must always be unique.