What are the advantages and disadvantages of creating a separate table for tracking read threads versus using a single table with multiple columns for each user?

When tracking read threads for multiple users, you can either create a separate table to store this information or use a single table with multiple columns for each user. Advantages of using a separate table: 1. Easier to manage and query specific user's read threads. 2. Allows for more flexibility in adding additional features related to read threads. 3. Simplifies the database structure and improves performance for large datasets. Disadvantages of using a separate table: 1. Requires additional joins to retrieve data across multiple tables. 2. Increases the complexity of the database schema. 3. May lead to redundant data storage if not properly normalized. Advantages of using a single table with multiple columns for each user: 1. Simplifies data retrieval by having all information in one table. 2. Reduces the need for joins when querying data. 3. Can be more efficient for small datasets or simple applications. Disadvantages of using a single table with multiple columns for each user: 1. Limited scalability as the table grows with more users. 2. Increases the risk of data redundancy and inconsistency. 3. Makes it harder to add new features or modify existing ones related to read threads.

// Using a separate table for tracking read threads
CREATE TABLE user_read_threads (
    user_id INT,
    thread_id INT,
    last_read_at DATETIME,
    PRIMARY KEY (user_id, thread_id),
    FOREIGN KEY (user_id) REFERENCES users(id),
    FOREIGN KEY (thread_id) REFERENCES threads(id)
);

// Using a single table with multiple columns for each user
CREATE TABLE user_read_threads (
    user_id INT,
    thread1_read_at DATETIME,
    thread2_read_at DATETIME,
    thread3_read_at DATETIME,
    PRIMARY KEY (user_id),
    FOREIGN KEY (user_id) REFERENCES users(id)
);