added STEP 1, 3, 4.3

skonev/greenplum/STEP1.2_create_tables.sql

@@ -0,0 +1,44 @@
+--создаем таблицы для raw слоя с DISTRIBUTED REPLICATED, т.к. таблицы довольно маленькие 
+
+
+CREATE TABLE raw.users (
+	id BIGINT PRIMARY KEY, 
+	name VARCHAR(100), 
+	age INT, 
+	email VARCHAR(255) UNIQUE, 
+	registration_date DATE NOT NULL
+)
+DISTRIBUTED REPLICATED;
+
+CREATE TABLE raw.courses(
+	id BIGINT PRIMARY KEY,
+	title TEXT NOT NULL,
+	category VARCHAR(255) CHECK (category IN ('data', 'programming', 'business')),
+	created_at DATE NOT NULL
+	)
+	DISTRIBUTED REPLICATED;
+
+CREATE TABLE raw.lessons(
+	id BIGINT PRIMARY KEY, 
+	course_id INT NOT NULL,
+	title TEXT NOT NULL, 
+	duration_min INT NOT NULL
+	)
+	DISTRIBUTED REPLICATED;
+
+
+CREATE TABLE raw.enrollments(
+	id BIGINT PRIMARY KEY, 
+	user_id INT NOT NULL,
+	course_id INT NOT NULL,
+	enrolled_at DATE NOT NULL
+	)
+	DISTRIBUTED REPLICATED;
+
+CREATE TABLE raw.lesson_views(
+	id BIGINT PRIMARY KEY, 
+	user_id INT NOT NULL,
+	lesson_id INT NOT NULL,
+	viewed_at TIMESTAMP NOT NULL
+	)
+	DISTRIBUTED REPLICATED;