ARNAV69420/databaseAssignment

repo for database assignments

Chat Server

Arnav Kumar Behera

This folder contains the source code for

• Lossless Join Testing

• Lossless and Dependency Preserving Decomposition into 3NF

• Lossless Decomposition into BCNF

Features

• Written in C++
• Command Line Interface
• Easy on the eyes and simple to use.

Prerequisites

• gcc 11.3.0

• C++20 standard

How to get it running?

Change working directory into the directory that contains the folde

• Way 1:

The three codes are in C++ and can be compiled and executed using g++.

    #-------------------------------------
    # filename can be
    # ljt.cpp(for lossless join testing) 
    # 3nf.cpp (for decomposition into 3nf) 
    # bcnf.cpp(for lossless decomposition ) 
    #-------------------------------------
    g++ <filename> -o <executable filename>
    ./<executable filename>

• Way2 (Easier and Recommended):

    # Run this in terminal before executing any commands
    source make.sh
    
    # To run this in command line you can use the run command
    # usage: run filename(without cpp extension) see usage below VVV
    
    run bcnf            # similarly you can use run 3nf or run ljt
    
    # To run this from file input(input.txt) and write to file(output.txt)
    # usage: run_file filename(without cpp extension) see usage below VVV
    
    run_file bcnf       # similarly you can use run_file 3nf or run_file ljt

Input Format

Lossless Join Testing :

• First line is n (an integer denoting the number of attributes in base table)
• These attributes will be named A,B,C.. so write the FDs keeping those in mind
• Second line is m (an integer denoting the number of attributes in base table)
• The next m lines are the functional dependencies of the base table ( in format A>BC no spaces)
• This line is q (an integer denoting the number of derived tables)
• The next q lines represent the attributes in the derived tables (no spaces)

Sample Input 1:

5
4
E>D
D>E
C>AD
AB>C
2
ABC
CDE

Output 1: The above decomposition does not satisfy lossless join property

Sample Input 2:

5
4
E>D
D>E
C>AD
AB>C
2
ABC
CDE

Output 2: The above decomposition satisfies lossless join property

Lossless and Dependency Preserving Decomposition into 3NF:

• First line is n (an integer denoting the number of attributes in base table)
• Second line is s (a string denoting the attributes in base table (no spaces))
• This line is q (an integer denoting the number of derived tables)
• The next q lines are the functional dependencies of the base table ( in format A>BC no spaces)

Sample Input:

7
ABCDEFG
3
A>CDE
B>FG
AB>CDEFG

Sample Output:

R1(ACDE)
R2(BFG)
R3(AB) 

Lossless Decomposition into BCNF:

• First line is n (an integer denoting the number of attributes in base table)
• Second line is s (a string denoting the attributes in base table (no spaces))
• This line is q (an integer denoting the number of derived tables)
• The next q lines are the functional dependencies of the base table ( in format A>BC no spaces)

Sample Input 1:

6
ABCDEF
4
A>BC
CD>E
B>D
E>A

Output 1:

R1(ABC)
R2(ADE)
R3(AF)

Sample Input 2:

6
ABCDEF
5
A>BC
CD>E
B>D
E>A
A>F

Output 2:

R1(BD)
R2(ABCEF)

Have fun trying it out.

License

MIT

Contact

20CS01070@iitbbs.ac.in