Data Structure Of Using Hash Table

2110 Words Nov 25th, 2014 9 Pages
Overview:
Hashing in terms of encryption is the conversion of a word into a usually fixed-length value or key that represents the original word. Hashing is used to index and retrieve items in a database because it is faster to find the item using the shorter hashed key than to find it using the original value. It basically uses a hash function to convert the word into the key. Hash function is one that is used to map data of random size to data of fixed size. Values that are returned from a hash function are called as hash values, hash codes, or hash sums. It mainly uses hash table as a data structure to look up data rapidly. There will be no two words with same hash value, otherwise collision occurs between the two words.
In software programming, a hash table or hash map is a data structure that is used to execute an array i.e. it is a structure that can map keys to values. A hash function is used to determine an index value for an array of buckets or slots, with which we can find the correct value. A good hash function with an algorithm are essential for good performance of the hash table though it can be difficult to achieve. A basic requirement of a hash function is that it should provide distribution of hash values uniformly. If the distribution is non-uniform, it increases the number of collisions and the cost of resolving them. Uniformity can be evaluated by observing statistical tests. If for example there exists uniform distribution only for table sizes that are…
Open Document