-- Измерение пользователей
CREATE TABLE core.dim_user (
    user_id INT PRIMARY KEY,
    name TEXT,
    age INT,
    email TEXT,
    registration_date DATE
)
DISTRIBUTED BY (user_id);

-- Измерение курсов
CREATE TABLE core.dim_course (
    course_id INT PRIMARY KEY,
    title TEXT,
    category TEXT
)
DISTRIBUTED BY (course_id);

-- Измерение уроков
CREATE TABLE core.dim_lesson (
    lesson_id INT PRIMARY KEY,
    title TEXT,
    duration_min INT,
    course_id INT REFERENCES core.dim_course(course_id)
)
DISTRIBUTED BY (lesson_id);

-- Опционально: измерение времени
CREATE TABLE core.dim_date (
    date DATE PRIMARY KEY,
    year INT,
    month INT,
    day INT,
    weekday TEXT
)
DISTRIBUTED BY (date);

CREATE TABLE core.fact_lesson_views (
    user_id INT REFERENCES core.dim_user(user_id),
    lesson_id INT REFERENCES core.dim_lesson(lesson_id),
    course_id INT REFERENCES core.dim_course(course_id),
    viewed_at TIMESTAMP
)
DISTRIBUTED BY (user_id);

CREATE TABLE core.enrollments (
    user_id INT REFERENCES core.dim_user(user_id),
    course_id INT REFERENCES core.dim_course(course_id),
    enrolled_at TIMESTAMP
)
DISTRIBUTED BY (user_id);