Hashing Types

What is Hash File Organization?

Hash file organization may be a strategy of putting away and getting to information in a record employing a hash work to calculate the address of the information within the record....

Hashing Technique

Data is stored in data blocks at addresses generated using a hash function. The location where these records are stored is called a data block or data bucket. In this organization, records are stored at known addresses rather than by location. To write a record, the address is first calculated by applying a mathematical function to obtain the record’s key. The data record is saved to the generated address. In this case, the records are stored in BUCKETS, which are storage units that can store one or more records. For example, the hash function h(K) = K mod 7 hashes 35 and 43 to addresses 0, 1, as shown below,...

Hashing Types

There are two types of hashing such as:...

Static Hashing

If you specify a search key value, the hash function always calculates the same address. If you want to generate an address that uses a mod 5 hash function, only 5 different values ​​will be generated. The output address of this function is always the same. The number of available buckets always remains constant. Bucket addresses generated with static hashing always remain the same....

Dynamic Hashing

In dynamic hashing, Data buckets grow or shrink (dynamically added or removed) as the data set grows or shrinks. Dynamic Hashing is also known as Extended Hashing. Dynamic hashing requires the hash function to generate a large number of values....

Conclusion

Hashing is an efficient technique for locating desired data directly on disk without using index structures. Hashing techniques are useful when you want to retrieve specific data as when searching through all index values ​​to reach the desired data becomes very inefficient....

Frequently Asked Questions on Hash File Organization – FAQs

What are the advantages of Hash File Organization?...