A hash key is a small value that is used to represent a large part of the data in a hash system. A hash function is a mathematical equation that simplifies large amounts of data into small values. This process saves space in a database and makes information retrieval faster and easier for programs. It is also common to use hash systems to locate repeated information in complex systems, such as a repeated pattern of voice or image or even repeated portions of a DNA strand or deoxyribonucleic acid genome. Also, the hash key is the international English term for the # key on a phone or keyboard.
A hash key is a small value that is used to represent a large part of the data in a hash system.
A hash system works through a mathematical system that transforms information into a series of hash numeric keys. The original information for each hash key is stored in a list called a hash table. When a system searches for information but finds a key, it simply cross-references the key to the table and retrieves the original information.
When used in a database, a hash system is used for efficiency and speed. These systems break down large amounts of information into smaller bits, a process that saves database space and reduces the amount of time needed to submit information. For example, the name John Smith may appear repeatedly in a database. The hash system can represent that specific sequence of letters with the value ’01’.
In the example above, John Smith is ten characters including space, and 01 is just two. When the database gets the information and returns the hash key 01, it checks its hash table and sends ‘John Smith’. Since the hash key is only 20% of the actual value of the information, it saves space on each occurrence of the information; It also saves a lot of time on transmission.
Other systems will use a hash key to find redundant data. When a system contains large amounts of data that must be classified by redundancies or patterns, it is often easier to encode the information than to manually classify it. Since different hash algorithms hash information in different ways, data is often sent through multiple hash methods. When the hashing is complete, patterns can be found very quickly using the resulting hash tables.
In the United States, this key is often called the pound key, and the symbol is either a pound or a number sign. In Canada, the key is often called a numeric key. Almost everyone in the English-speaking world outside of North America calls it a hash key.
