🗃️ Extendible Hashing

A block level implementation of Extendible Hashing for both primary and secondary indexing in database systems.
Implementation of SQL Inner Join is also included.

A tiny database example

The next images show the hashing of the following records using both primary and secondary indexing.

ID	NAME	SURNAME	CITY
0	Dimitrios	Hardy	Los Angeles
1	Gabriel	Kyriakopoulos	Philadelphia
2	Angelos	Sheeran	New Work
3	Will	Jolie	Milwaukee
4	Angelina	Antetokounmpo	London
5	Giannis	Antetokounmpo	Athens
6	Gabriel	Rontogiannis	Halifax
7	Dimitrios	Smith	Athens
8	Dimitrios	Smith	Los Angeles

Primary Indexing Extendible Hashing

Secondary Indexing Extendible Hashing

Note: The secondary hashing is performed on the Surname key, as shown in the following screenshot.

Usage

A block level library named BlockFile is given for managing the memory.
Warning! The library is only compatible with linux machines, so you must be connected to a linux machine to run this repository. In order to run primary and/or secondary extendible hashing indexing just open a terminal in the current directory and do the following:

$ make primary    # Compiles primary indexing
$ make secondary  # Compiles secondary indexing
$ make runp       # Runs primary
$ make runs       # Runs secondary

$ make clean 

Authors

• Angelos Poulis^*
• Dimitrios Kyriakopoulos^*
• Dimitrios Rontogiannis^*

^*Equal contribution.