diff --git a/mnoskov/postgresql/Пет-проект: Онлайн-курсы/2. Создание отчетности (витрин)/DQL_materialized_view_cohort_analysis_of_users.sql b/mnoskov/postgresql/Пет-проект: Онлайн-курсы/2. Создание отчетности (витрин)/DQL_materialized_view_cohort_analysis_of_users.sql
new file mode 100644
index 0000000..19b8668
--- /dev/null
+++ b/mnoskov/postgresql/Пет-проект: Онлайн-курсы/2. Создание отчетности (витрин)/DQL_materialized_view_cohort_analysis_of_users.sql	
@@ -0,0 +1,40 @@
+CREATE MATERIALIZED VIEW user_cohort_analysis AS
+WITH users_and_enrollments_results AS (
+	SELECT
+		date_trunc('month', u.registration_date)::date AS cohort_month,
+		count(DISTINCT u.id) AS users_in_cohort,
+		count(DISTINCT e.user_id) AS enrolled_users,
+		count(DISTINCT e.course_id) courses_in_cohort
+	FROM
+		users u
+	JOIN
+		enrollments e ON u.id = e.user_id
+	GROUP BY
+		cohort_month
+),
+lesson_views_results AS (
+	SELECT
+		date_trunc('month', u.registration_date)::date AS cohort_month,
+		count(DISTINCT lv.user_id) AS active_users,
+		round(avg(lv.viewed_at::date - u.registration_date::date), 0) AS avg_time_to_first_view
+	FROM
+		users u
+	LEFT JOIN
+		lesson_views lv ON u.id = lv.user_id
+	GROUP BY
+		cohort_month	
+)
+SELECT
+	uer.cohort_month,
+	uer.users_in_cohort,
+	uer.enrolled_users,
+	lvr.active_users,
+	round((lvr.active_users / uer.users_in_cohort::numeric) * 100, 2) || '%' AS retention_rate,
+	round(uer.courses_in_cohort / uer.users_in_cohort::numeric, 2) AS avg_courses_per_user,
+	lvr.avg_time_to_first_view
+FROM
+	users_and_enrollments_results uer
+JOIN
+	lesson_views_results lvr ON uer.cohort_month = lvr.cohort_month
+ORDER BY
+	uer.cohort_month;
\ No newline at end of file