diff --git a/dmedvedev/11.4 Pet project Cohort_analysis.sql b/dmedvedev/11.4 Pet project Cohort_analysis.sql
new file mode 100644
index 0000000..0411e70
--- /dev/null
+++ b/dmedvedev/11.4 Pet project Cohort_analysis.sql	
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+CREATE MATERIALIZED VIEW user_cohort_analysis AS
+
+	SELECT 
+		TO_CHAR(pu.cohort_month, 'YYYY-MM') AS MONTH,
+		COUNT(DISTINCT pu.id) AS users_in_cohort,
+		COUNT(DISTINCT pe.user_id) AS enrolled_users,
+		COUNT(DISTINCT plv.user_id) AS active_users,
+		ROUND(COUNT(DISTINCT plv.user_id) * 100.0 / COUNT(DISTINCT pu.id), 2) || '%' AS retention_rate,
+		ROUND(AVG((SELECT COUNT(*) FROM pet_courses pc)) / COUNT(DISTINCT pu.id), 2) AS avg_courses_per_user,	
+		(SELECT 
+			ROUND(AVG(table_first_viewed_at.first_viewed_at::date - pu2.registration_date::date), 2)
+		FROM pet_users pu2
+		LEFT JOIN (
+			SELECT 
+				plv2.user_id,
+				MIN(plv2.viewed_at) AS first_viewed_at
+			FROM pet_lesson_views plv2
+			GROUP BY plv2.user_id
+		) AS table_first_viewed_at
+		
+			ON pu2.id = table_first_viewed_at.user_id
+			
+		WHERE DATE_TRUNC('month', pu2.registration_date) = pu.cohort_month
+		) AS avg_time_to_first_view
+		
+	FROM (
+		SELECT
+			*,
+			DATE_TRUNC('month', registration_date) AS cohort_month
+		FROM pet_users
+	) AS pu
+	LEFT JOIN pet_enrollments pe ON pu.id = pe.user_id
+	LEFT JOIN pet_lesson_views plv ON pu.id = plv.user_id
+	
+	GROUP BY pu.cohort_month
+	ORDER BY pu.cohort_month;
+
+