InMemoryDB

InMemoryDB is a single-table in-memory database that I built from scratch. It handles CRUD operations for a single table with a primary key. This project contains a server side and a client side application. The client connects to the server and starts querying SQL commands. The server parses SQL commands and perform the required operations.

Build

To build and generate the java jar files run the following maven command:

mvn clean package

After this, you will find the jar file of the server application under ServerSide/target/Server.jar. And you will find the jar file of the client under ClientSide/target/Client.jar. Copy the jars wherever you want and cd to that directory.

Run

To run the server you will have to create a user first by running:

java -cp Server.jar Server.ServerAdmin

It will prompt you for operations to manage users. Choose to add a user and provide a username and a password.

To run the server :

java -jar Server.jar

To run the client:

java -jar Client.jar <Server Address> <Port Number>

The default port number is 7979. But you can change that in the configurations.

Configuration

To configure the server, create a file with the name config.porperties in the same directory where you run the Server.jar from. Then, add the following properties and change them as you wish:

cache_size = 500
server_port = 7979
users_directory = Users
records_directory = Records

Table

The database table of this project is named students, and it has these attributes:

• id
• name
• faculty
• major
• credit_hours
• gpa

for example, you can query these SQL commands from the client side:

• select id, name, major, gpa from students;
• insert into students (id, name, major) values(1, "Malek", "Computer Engineering");
• select * from students where gpa > 3.4;
• update students set credit_hours = 132 where faculty = "Engineering";
• delete from students where credit_hours < 132;