DBMS

This project was created for academic purposes on the subject of 'Database Technology' at the Aristotle University of Thessaloniki.

This project contains basic functions of a DBMS (External Merge sort, Duplicate Elimination, Merge Join, Hash Join) that are designed to work in real-life and extreme circumstances (Huge input data, extremely low available memory).

Examples

Input:

- N: number of blocks in the file, N1: number of blocks in the file1, N2: number of blocks in the file2
- B: number of blocks in the memory buffer
- field: which field will be used for sorting: 0 is for recid, 1 is for num, 2 is for str and 3 is for both num and str

Output:

- nsorted_segs: number of sorted segments produced 
- npasses: number of passes required for sorting 
- nios: number of IOs performed 

External Merge sort

-Input File-

1. N = 10, B = 3, MAX_RECORDS_PER_BLOCK = 10, field = 1

-Output File-

2. N = 10, B = 3, MAX_RECORDS_PER_BLOCK = 10, field = 2

-Output File-

Duplicate Elimination

-Input File-

1. N = 10, B = 4, MAX_RECORDS_PER_BLOCK = 10, field = 1

-Output File-

2. N = 10, B = 4, MAX_RECORDS_PER_BLOCK = 10, field = 2

-Output File-

Merge Join

-Input File 1 & Input File 2-

N1 = 10, N2 = 10, B = 3, MAX_RECORDS_PER_BLOCK = 10, field = 1

-Output File-

Hash Join

-Input File 1 & Input File 2-

N1 = 10, N2 = 10, B = 3, MAX_RECORDS_PER_BLOCK = 10, field = 1

-Output File-

More examples in bigger input data sets

MergeSort:

EliminateDuplicates:

MergeJoin & ΗashJoin: