Merge pull request 'Polikanov63' (#21) from Polikanov63 into main

Reviewed-on: https://gitea.de-infra.servehttp.com/de-infrastructure/DWH/pulls/21
Reviewed-by: aleksey bogatyrev <abogatyrev@example.com>

APolikanov/1 - Пет-проект_Онлайн-курсы/1.1 DDL_CREATE_TABLE.SQL

@@ -0,0 +1,50 @@
+DROP SCHEMA IF EXISTS edu_platform CASCADE;
+CREATE SCHEMA edu_platform;
+
+drop table if exists edu_platform.users;
+CREATE TABLE edu_platform.users (
+    id SERIAL PRIMARY KEY,
+    name VARCHAR(100) NOT NULL,
+    age INT NOT NULL,
+    email VARCHAR(100) NOT NULL, 
+    registration_date DATE NOT NULL
+);
+
+drop table if exists edu_platform.courses;
+CREATE TABLE edu_platform.courses (
+	id SERIAL PRIMARY KEY,
+	title VARCHAR(100) NOT NULL,
+	category VARCHAR(100) NOT NULL,
+    created_at DATE not NULL
+);
+
+drop table if exists edu_platform.lessons;
+create TABLE edu_platform.lessons (
+	id SERIAL PRIMARY KEY,
+	course_id INT NOT NULL,
+	title VARCHAR(100) NOT NULL,
+	duration_min INT NOT null,
+	FOREIGN KEY (course_id) REFERENCES edu_platform.courses(id)
+);
+
+drop table if exists edu_platform.enrollments;
+create TABLE edu_platform.enrollments (
+	id SERIAL PRIMARY KEY,
+	user_id	INT NOT NULL,
+	course_id INT NOT NULL,
+	enrolled_at DATE not null,
+	foreign key (user_id) references edu_platform.users(id),
+	foreign key (course_id) references edu_platform.courses(id)
+);
+
+drop table if exists edu_platform.lesson_views;
+create table edu_platform.lesson_views (
+	id SERIAL PRIMARY KEY,
+	user_id	INT NOT NULL,
+	lesson_id INT NOT NULL,
+	viewed_at TIMESTAMP not null,
+	foreign key (user_id) references edu_platform.users(id),
+	foreign key (lesson_id) references edu_platform.lessons(id)
+);
+
+

APolikanov/1 - Пет-проект_Онлайн-курсы/1.2 DML_INSERT_DATA.SQL

@@ -0,0 +1,38 @@
+INSERT INTO edu_platform.users (id, name, age, email, registration_date) VALUES 
+(1, 'Alice', 25, 'alice@mail.com', '2023-01-10'),
+(2,'Bob', 30, 'bob@gmail.com', '2023-02-05'),
+(3,'Charlie', 22, 'charlie@mail.com', '2023-02-20'),
+(4,'Diana', 28, 'diana@mail.com', '2023-03-01'),
+(5,'Ethan', 35, 'ethan@gmail.com', '2023-03-10');
+    
+    
+
+INSERT INTO edu_platform.courses (id, title, category, created_at) VALUES
+(1, 'SQL для начинающих', 'data', '2023-01-01'),
+(2, 'Python для анализа данных', 'programming', '2023-01-15'),
+(3, 'BI с нуля', 'business', '2023-03-01');
+
+-- Таблица lessons
+INSERT INTO edu_platform.lessons (id, course_id, title, duration_min) VALUES
+(1, 1, 'SELECT и FROM', 10),
+(2, 1, 'JOIN', 15),
+(3, 2, 'Pandas', 20),
+(4, 3, 'Основы BI', 12),
+(5, 3, 'Метрики и дашборды', 18);
+
+-- Таблица enrollments
+INSERT INTO edu_platform.enrollments (id, user_id, course_id, enrolled_at) VALUES
+(1, 1, 1, '2023-01-15'),
+(2, 1, 2, '2023-02-01'),
+(3, 2, 1, '2023-01-20'),
+(4, 3, 2, '2023-03-05'),
+(5, 4, 3, '2023-04-01');
+
+-- Таблица lesson_views
+INSERT INTO edu_platform.lesson_views (id, user_id, lesson_id, viewed_at) VALUES
+(1, 1, 1, '2023-01-16 10:00:00'),
+(2, 1, 2, '2023-01-16 10:15:00'),
+(3, 2, 1, '2023-01-21 09:00:00'),
+(4, 3, 3, '2023-03-06 12:00:00'),
+(5, 4, 4, '2023-04-02 10:00:00'),
+(6, 4, 5, '2023-04-03 10:00:00');

APolikanov/1 - Пет-проект_Онлайн-курсы/2.1 DDL_CREATE_MAT_VIEW_user_activity_summary.sql

@@ -0,0 +1,74 @@
+-- Активность пользователей
+
+-- До анализа EXPLAIN:
+drop  Materialized VIEW if exists edu_platform.user_activity_summary;
+create Materialized VIEW edu_platform.user_activity_summary as 
+select
+	u.id as user_id ,
+	u.name as name,
+	COUNT(distinct e.course_id) as enrollment_count,
+	COUNT(distinct lv.lesson_id) as viewed_lessons_count,
+	MAX(lv.viewed_at) as last_view,
+	MIN(lv.viewed_at) as first_view,
+	ROUND(
+		COUNT(DISTINCT l.id) * 100.0 / NULLIF(COUNT(distinct l2.id), 0), 
+		2) as engagement_rate
+from
+	edu_platform.users u 
+left join edu_platform.enrollments e on u.id = e.user_id
+inner join edu_platform.lesson_views lv on u.id = lv.user_id
+left join edu_platform.lessons l on lv.lesson_id  = l.id
+left join edu_platform.lessons l2 on e.course_id  = l2.course_id
+group by 
+	u.id, u.name;
+
+-- После анализа EXPLAIN
+-- Убрал диблирование строк, возникающее при Join-ах.
+-- Минимизировал DISTINCT.
+
+
+drop  Materialized VIEW if exists edu_platform.user_activity_summary;
+create Materialized VIEW edu_platform.user_activity_summary as 
+WITH 
+course_lessons AS (
+    SELECT course_id, COUNT(*) AS lesson_count
+    FROM edu_platform.lessons
+    GROUP BY course_id
+),
+users_enroll as (
+	select
+		u.id as user_id ,
+		u.name as name,
+		COUNT(DISTINCT e.course_id) as enrollment_count,
+		SUM(cl.lesson_count) as lesson_sum
+	from
+		edu_platform.users u
+	left join edu_platform.enrollments e on u.id = e.user_id
+	left join course_lessons cl on e.course_id = cl.course_id
+	group by u.id, u.name
+),
+users_lesson_views as (
+	select
+		lv.user_id,
+		COUNT(distinct lv.lesson_id) as viewed_lessons_count,
+		MAX(lv.viewed_at) as last_view,
+		MIN(lv.viewed_at) as first_view
+	from
+		edu_platform.lesson_views lv
+	group by lv.user_id
+)
+select 
+	ue.user_id,
+	ue.name,
+	ue.enrollment_count,
+	ulv.viewed_lessons_count,
+	ulv.last_view,
+	ulv.first_view,
+	ROUND( (nullif(ulv.viewed_lessons_count, 0) * 100.0) / ue.lesson_sum,
+	2) as engagement_rate
+from users_enroll ue
+left join users_lesson_views ulv on ue.user_id = ulv.user_id;
+
+
+
+

APolikanov/1 - Пет-проект_Онлайн-курсы/2.2 DDL_CREATE_MAT_VIEW_course_summary.sql

@@ -0,0 +1,51 @@
+-- Эффективность курсов
+
+-- После анализа EXPLAIN
+-- Убрал диблирование строк, возникающее при Join-ах.
+-- Минимизировал DISTINCT.
+drop  Materialized VIEW if exists edu_platform.course_summary;
+create Materialized VIEW edu_platform.course_summary as 
+with
+enroll as (
+	select 
+		course_id, 
+		COUNT(DISTINCT user_id) as unique_users -- Может ли один и тот же юзер записаться на курс больше одного раза? Если да, то нужен DISTINCT
+	from 
+		edu_platform.enrollments 
+	group by 
+		course_id),
+lessons as (
+	select 
+		course_id,
+		COUNT(*) as lessons_count
+	from 
+		edu_platform.lessons
+	group by 
+		course_id),
+views as (
+	select 
+		l.course_id as course_id,
+		count(*) as total_views,
+		MIN(lv.viewed_at) as first_view,
+		MAX(lv.viewed_at) as last_view
+	from 
+		edu_platform.lesson_views lv
+	left join edu_platform.lessons l on lv.lesson_id = l.id
+	group by 
+		l.course_id)
+select
+    c.id AS course_id,
+    c.title AS course_title,
+	e.unique_users,
+	l.lessons_count,
+	v.total_views,
+	ROUND( v.total_views * 1.0 / nullif(e.unique_users, 0)
+		,2
+		) as avg_views_per_user,
+	v.first_view,
+	v.last_view
+from
+	edu_platform.courses c
+LEFT JOIN enroll e ON c.id = e.course_id
+LEFT JOIN lessons l ON c.id = l.course_id
+LEFT JOIN views v ON c.id = v.course_id;

APolikanov/1 - Пет-проект_Онлайн-курсы/2.3 DDL_CREATE_MAT_VIEW_platform_summary.sql

@@ -0,0 +1,21 @@
+-- Общая отчетность по взаимодействию
+
+drop  Materialized VIEW if exists edu_platform.platform_summary;
+create Materialized VIEW edu_platform.platform_summary as 
+select
+	(select COUNT(*) from edu_platform.users) as total_users,
+	(select COUNT(*) from edu_platform.courses) as total_courses,
+	(select COUNT(*) from edu_platform.lessons) as total_lessons,
+	(select COUNT(distinct user_id) from edu_platform.lesson_views) as users_with_views,
+	ROUND(
+		(select AVG(t1.cnt) from 
+			(select course_id, COUNT(id) cnt 
+			from edu_platform.lessons 
+			group by course_id) t1) 
+		,2) as avg_lessons_per_course,
+	ROUND(
+		(select AVG(t2.cnt) from
+			(select lesson_id, COUNT(id) cnt 
+			from edu_platform.lesson_views 
+			group by lesson_id) t2)	
+		,2) as avg_views_per_lesson;

APolikanov/2 - GreenPlum-Pet-project/1 DDL_CREATE_SCHEMA_AND_TABLE.sql

@@ -0,0 +1,64 @@
+-- 0. Создаём БД
+CREATE DATABASE dwh_db
+    WITH OWNER = tester
+         TEMPLATE = template0
+         ENCODING = 'UTF8';
+
+-- 1. Создём схемы
+CREATE SCHEMA raw;      -- сырые данные
+CREATE SCHEMA core;     -- или core. Тут хранилище: факты и измерения
+CREATE SCHEMA dm;       -- BI-витрины
+
+
+-- 2. Создаём raw-таблицы:
+
+CREATE TABLE raw.users (
+	id serial4 NOT NULL,
+	"name" varchar(100) NOT NULL,
+	age int4 NOT NULL,
+	email varchar(100) NOT NULL,
+	registration_date date NOT NULL,
+	CONSTRAINT users_pkey PRIMARY KEY (id)
+)
+DISTRIBUTED BY (id);
+
+CREATE TABLE raw.courses (
+	id serial4 NOT NULL,
+	title varchar(100) NOT NULL,
+	category varchar(100) NOT NULL,
+	created_at date NOT NULL,
+	CONSTRAINT courses_pkey PRIMARY KEY (id)
+)
+DISTRIBUTED BY (id);
+
+CREATE TABLE raw.lessons (
+	id serial4 NOT NULL,
+	course_id int4 NOT NULL,
+	title varchar(100) NOT NULL,
+	duration_min int4 NOT NULL,
+	CONSTRAINT lessons_pkey PRIMARY KEY (id)
+)
+DISTRIBUTED BY (id);
+ALTER TABLE raw.lessons ADD CONSTRAINT lessons_course_id_fkey FOREIGN KEY (course_id) REFERENCES raw.courses(id);
+
+CREATE TABLE raw.enrollments (
+	id serial4 NOT NULL,
+	user_id int4 NOT NULL,
+	course_id int4 NOT NULL,
+	enrolled_at date NOT NULL,
+	CONSTRAINT enrollments_pkey PRIMARY KEY (id)
+)
+DISTRIBUTED BY (id);
+ALTER TABLE raw.enrollments ADD CONSTRAINT enrollments_course_id_fkey FOREIGN KEY (course_id) REFERENCES raw.courses(id);
+ALTER TABLE raw.enrollments ADD CONSTRAINT enrollments_user_id_fkey FOREIGN KEY (user_id) REFERENCES raw.users(id);
+
+CREATE TABLE raw.lesson_views (
+	id serial4 NOT NULL,
+	user_id int4 NOT NULL,
+	lesson_id int4 NOT NULL,
+	viewed_at timestamp NOT NULL,
+	CONSTRAINT lesson_views_pkey PRIMARY KEY (id)
+)
+DISTRIBUTED BY (id);
+ALTER TABLE raw.lesson_views ADD CONSTRAINT lesson_views_lesson_id_fkey FOREIGN KEY (lesson_id) REFERENCES raw.lessons(id);
+ALTER TABLE raw.lesson_views ADD CONSTRAINT lesson_views_user_id_fkey FOREIGN KEY (user_id) REFERENCES raw.users(id);

APolikanov/2 - GreenPlum-Pet-project/2 DDM_IMPORT_DATA_TO_RAW.SQL

@@ -0,0 +1,48 @@
+/* Копирую в файлы в контейнер:
+docker cp D:/work/code/DE/GP/Pet-project/IMPORT_DATA/users_202512050730.csv gpdb1:/tmp/users_202512050730.csv
+docker cp D:/work/code/DE/GP/Pet-project/IMPORT_DATA/courses_202512050730.csv gpdb1:/tmp/courses_202512050730.csv
+docker cp D:/work/code/DE/GP/Pet-project/IMPORT_DATA/enrollments_202512050730.csv gpdb1:/tmp/enrollments_202512050730.csv
+docker cp D:/work/code/DE/GP/Pet-project/IMPORT_DATA/lesson_views_202512050730.csv gpdb1:/tmp/lesson_views_202512050730.csv
+docker cp D:/work/code/DE/GP/Pet-project/IMPORT_DATA/lessons_202512050730.csv gpdb1:/tmp/lessons_202512050730.csv
+*/
+
+
+COPY raw.users
+FROM '/tmp/users_202512050730.csv'
+WITH (
+    FORMAT csv,
+    HEADER true,
+    DELIMITER ','
+);
+
+COPY raw.courses
+FROM '/tmp/courses_202512050730.csv'
+WITH (
+    FORMAT csv,
+    HEADER true,
+    DELIMITER ','
+);
+
+COPY raw.lessons
+FROM '/tmp/lessons_202512050730.csv'
+WITH (
+    FORMAT csv,
+    HEADER true,
+    DELIMITER ','
+);
+
+COPY raw.enrollments
+FROM '/tmp/enrollments_202512050730.csv'
+WITH (
+    FORMAT csv,
+    HEADER true,
+    DELIMITER ','
+);
+
+COPY raw.lesson_views
+FROM '/tmp/lesson_views_202512050730.csv'
+WITH (
+    FORMAT csv,
+    HEADER true,
+    DELIMITER ','
+);

APolikanov/2 - GreenPlum-Pet-project/3 DDL_CREATE_CORE.sql

@@ -0,0 +1,51 @@
+-- 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);

APolikanov/2 - GreenPlum-Pet-project/6.1 DDM_INSERT_IN_CORE_dim_user.sql

@@ -0,0 +1,49 @@
+BEGIN;
+-- UPDATE с проверкой изменений
+update
+	core.dim_user d
+set
+	name = s.name,
+	age = s.age,
+	email = s.email,
+	registration_date = s.registration_date
+from
+	(
+	select
+		distinct
+        id::INT,
+		name::TEXT,
+		age::INT,
+		email::TEXT,
+		registration_date::DATE
+	from
+		raw.users
+) s
+where
+	d.user_id = s.id
+	and (
+       d.name is distinct from s.name
+	or d.age is distinct from s.age
+	or d.email is distinct from s.email
+	or d.registration_date is distinct from s.registration_date
+  );
+-- INSERT новых строк
+INSERT INTO core.dim_user (user_id, name, age, email, registration_date)
+SELECT
+    s.id,
+    s.name,
+    s.age,
+    s.email,
+    s.registration_date
+FROM (
+    SELECT DISTINCT
+        id::INT,
+        name::TEXT,
+        age::INT,
+        email::TEXT,
+        registration_date::DATE
+    FROM raw.users
+) s
+LEFT JOIN core.dim_user d on d.user_id = s.id
+WHERE d.user_id IS NULL;
+COMMIT;

APolikanov/2 - GreenPlum-Pet-project/6.2 DDM_INSERT_IN_CORE_dim_course.sql

@@ -0,0 +1,39 @@
+BEGIN;
+-- UPDATE с проверкой изменений
+update
+	core.dim_course dc
+set
+	title = s.title,
+	category = s.category
+from
+	(
+	select
+		distinct
+        id::INT,
+		title::TEXT,
+		category::TEXT
+	from
+		raw.courses
+) s
+where
+	dc.course_id = s.id
+	and (
+       dc.title is distinct from s.title
+	or dc.category is distinct from s.category
+  );
+-- INSERT новых строк
+INSERT INTO core.dim_course (course_id, title, category)
+SELECT
+    s.id,
+    s.title,
+    s.category
+FROM (
+    SELECT DISTINCT
+        id::INT,
+		title::TEXT,
+		category::TEXT
+    FROM raw.courses
+) s
+LEFT JOIN core.dim_course cd on cd.course_id = s.id
+WHERE cd.course_id IS NULL;
+COMMIT;

APolikanov/2 - GreenPlum-Pet-project/6.3 DDM_INSERT_IN_CORE_dim_lesson.sql

@@ -0,0 +1,44 @@
+BEGIN;
+-- UPDATE с проверкой изменений
+update
+	core.dim_lesson dl
+set
+	title = l.title,
+	duration_min = l.duration_min,
+	course_id = l.course_id
+from
+	(
+	select distinct
+        id::INT,
+        course_id::INT,
+		title::TEXT,
+		duration_min::INT
+	from
+		raw.lessons
+) l
+where
+	dl.lesson_id = l.id
+	and (
+       dl.title is distinct from l.title
+	or dl.duration_min is distinct from l.duration_min
+	or dl.course_id is distinct from l.course_id
+  );
+-- INSERT новых строк
+INSERT INTO core.dim_lesson (lesson_id, title, duration_min, course_id)
+SELECT
+    l.id,
+    l.title,
+    l.duration_min,
+    l.course_id
+FROM (
+	select distinct
+        id::INT,
+        course_id::INT,
+		title::TEXT,
+		duration_min::INT
+	from
+		raw.lessons
+) l
+LEFT JOIN core.dim_lesson dl on dl.lesson_id = l.id
+WHERE dl.lesson_id IS NULL;
+COMMIT;

APolikanov/2 - GreenPlum-Pet-project/6.4 DDM_INSERT_IN_CORE_enrollments.sql

@@ -0,0 +1,17 @@
+insert into core.enrollments (user_id, course_id, enrolled_at)
+select
+	re.user_id,
+	re.course_id,
+	re.enrolled_at
+from
+	(select DISTINCT
+		user_id::INT,
+		course_id::INT,
+		enrolled_at
+	from
+		raw.enrollments) re
+LEFT join core.enrollments ce on 
+	ce.user_id = re.user_id
+	and ce.course_id = re.course_id
+	and ce.enrolled_at = re.enrolled_at
+WHERE ce.user_id IS NULL;

APolikanov/2 - GreenPlum-Pet-project/6.5 DDM_INSERT_IN_CORE_fact_lesson_views.sql

@@ -0,0 +1,22 @@
+-- INSERT новых строк
+INSERT INTO  core.fact_lesson_views (user_id, lesson_id, course_id, viewed_at)
+select 
+	l.user_id,
+	l.lesson_id,
+	l.course_id,
+	l.viewed_at 
+from (select
+	lv.user_id,
+	lv.lesson_id,
+	l.course_id,
+	lv.viewed_at
+	from
+		raw.lesson_views lv
+	left join raw.lessons l on lv.lesson_id = l.id
+	) l
+LEFT join core.fact_lesson_views flv on 
+	flv.user_id = l.user_id
+	and flv.lesson_id = l.lesson_id
+	and flv.course_id = l.course_id
+	and flv.viewed_at = l.viewed_at 
+WHERE flv.user_id IS NULL;

APolikanov/2 - GreenPlum-Pet-project/7.1 DDL_CREATE_dm.lesson_popularity_summary.SQL

@@ -0,0 +1,29 @@
+DROP MATERIALIZED VIEW IF EXISTS dm.lesson_popularity_summary;
+CREATE MATERIALIZED VIEW dm.lesson_popularity_summary
+DISTRIBUTED BY (lesson_id)
+AS
+select
+	t1.lesson_id as lesson_id,
+	dl.title as lesson_title,
+	t1.course_id as course_id,
+	dc.title as course_title,
+	t1.total_views as total_views,
+	t1.unique_users as unique_users,
+	t1.first_view as first_view,
+	t1.last_view as last_view
+from
+	(select 
+		flv.lesson_id,
+		flv.course_id,
+		COUNT(*) as total_views,
+		COUNT(distinct flv.user_id) as unique_users,
+		MIN(flv.viewed_at) as first_view,
+		MAX(flv.viewed_at) as last_view
+	from 
+		core.fact_lesson_views flv
+	group by
+		flv.lesson_id,
+		flv.course_id
+		) as t1
+right join core.dim_lesson dl on dl.lesson_id = t1.lesson_id
+left join core.dim_course dc on t1.course_id = dc.course_id;

APolikanov/2 - GreenPlum-Pet-project/7.2 DDL_CREATE_dm.inactive_users_summary.SQL

@@ -0,0 +1,25 @@
+DROP MATERIALIZED VIEW IF EXISTS dm.inactive_users_summary;
+CREATE MATERIALIZED VIEW dm.inactive_users_summary
+DISTRIBUTED BY (user_id)
+AS
+select
+	du.user_id as user_id,
+	du.name as user_name,
+	du.email as email,
+	du.age as age,
+	COALESCE(e.enrollments_count, 0) as enrollments_count,
+	du.registration_date as registration_date
+from
+	core.dim_user du
+left join 
+	(select
+		user_id,
+		COUNT(*) as enrollments_count
+	from 
+		core.enrollments
+	group by
+		user_id
+		) e on du.user_id = e.user_id 
+left join core.fact_lesson_views flv on du.user_id = flv.user_id
+where
+	flv.user_id is null;

APolikanov/2 - GreenPlum-Pet-project/7.3 DDL_CREATE_dm.course_completion_rate.SQL

@@ -0,0 +1,39 @@
+DROP MATERIALIZED VIEW IF EXISTS dm.course_completion_rate;
+CREATE MATERIALIZED VIEW dm.course_completion_rate
+DISTRIBUTED BY (user_id)
+AS
+with activity_users as (
+select
+	e.user_id as user_id,
+	e.course_id as course_id,
+	COUNT(DISTINCT flv.viewed_at) as lessons_viewed
+from
+	core.enrollments e
+left join core.dim_lesson dl on e.course_id = dl.course_id
+left join core.fact_lesson_views flv on e.user_id = flv.user_id and e.course_id = flv.course_id and dl.lesson_id = flv.lesson_id
+group by
+	e.user_id,
+	e.course_id),
+course2 as (	
+	select
+		course_id,
+		COUNT(*) as lessons_in_course
+	from core.dim_lesson
+	group by 
+		course_id)
+select
+	au.user_id as user_id,
+	du.name as user_name,
+	au.course_id as course_id,
+	dc.title as course_title,
+	c2.lessons_in_course as lessons_in_course,
+	au.lessons_viewed as lessons_viewed,
+	ROUND(au.lessons_viewed * 1.0 / c2.lessons_in_course , 2) as completion_rate
+from
+	activity_users au
+left join core.dim_user du on au.user_id = du.user_id
+left join core.dim_course dc on au.course_id = dc.course_id
+left join course2 c2 on au.course_id = c2.course_id
+order by
+	au.user_id,
+	au.course_id;

APolikanov/2 - GreenPlum-Pet-project/IMPORT_DATA/courses_202512050730.csv

@@ -0,0 +1,4 @@
+"id","title","category","created_at"
+1,SQL для начинающих,data,2023-01-01
+2,Python для анализа данных,programming,2023-01-15
+3,BI с нуля,business,2023-03-01

APolikanov/2 - GreenPlum-Pet-project/IMPORT_DATA/enrollments_202512050730.csv

@@ -0,0 +1,6 @@
+"id","user_id","course_id","enrolled_at"
+1,1,1,2023-01-15
+2,1,2,2023-02-01
+3,2,1,2023-01-20
+4,3,2,2023-03-05
+5,4,3,2023-04-01

APolikanov/2 - GreenPlum-Pet-project/IMPORT_DATA/lesson_views_202512050730.csv

@@ -0,0 +1,7 @@
+"id","user_id","lesson_id","viewed_at"
+1,1,1,2023-01-16 10:00:00.000
+2,1,2,2023-01-16 10:15:00.000
+3,2,1,2023-01-21 09:00:00.000
+4,3,3,2023-03-06 12:00:00.000
+5,4,4,2023-04-02 10:00:00.000
+6,4,5,2023-04-03 10:00:00.000

APolikanov/2 - GreenPlum-Pet-project/IMPORT_DATA/lessons_202512050730.csv

@@ -0,0 +1,6 @@
+"id","course_id","title","duration_min"
+1,1,SELECT и FROM,10
+2,1,JOIN,15
+3,2,Pandas,20
+4,3,Основы BI,12
+5,3,Метрики и дашборды,18

APolikanov/2 - GreenPlum-Pet-project/IMPORT_DATA/users_202512050730.csv

@@ -0,0 +1,6 @@
+"id","name","age","email","registration_date"
+1,Alice,25,alice@mail.com,2023-01-10
+2,Bob,30,bob@gmail.com,2023-02-05
+3,Charlie,22,charlie@mail.com,2023-02-20
+4,Diana,28,diana@mail.com,2023-03-01
+5,Ethan,35,ethan@gmail.com,2023-03-10

test.txt

@@ -0,0 +1 @@
+test коммита в Gitea