diff --git a/mdrozdov/postgresql/create_tables.sql b/mdrozdov/postgresql/create_tables.sql
new file mode 100644
index 0000000..4b6f588
--- /dev/null
+++ b/mdrozdov/postgresql/create_tables.sql
@@ -0,0 +1,70 @@
+--drop table is exists users;
+create table users(
+	id int primary key,
+	name varchar(50) not null,
+	age int not null,
+	email varchar(50) not null,
+	registration_date date not null default current_date
+)
+
+insert into 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')
+
+create table courses(
+    id int primary key,
+    title text not null,
+    category varchar(30) not null,
+    created_at date not null default current_date
+)
+
+insert into 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');
+
+create table lessons(
+    id int primary key,
+    course_id int references courses(id), 
+    title text not null,
+    duration_min int
+)
+
+insert into 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)
+
+create table enrollments(
+    id int primary key,
+    user_id int references users(id),
+    course_id int references courses(id),
+    enrolled_at date not null default current_date
+)
+
+insert into 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')
+
+create table lessons_views(
+    id int primary key,
+    user_id int references users(id),
+    lesson_id int references lessons(id),
+    viewed_at timestamp not null default now()
+)
+
+insert into lessons_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')
\ No newline at end of file
diff --git a/mdrozdov/postgresql/dm_course_summary.sql b/mdrozdov/postgresql/dm_course_summary.sql
new file mode 100644
index 0000000..40b4b8d
--- /dev/null
+++ b/mdrozdov/postgresql/dm_course_summary.sql
@@ -0,0 +1,16 @@
+create materialized view dm_course_summary as
+select
+	e.course_id,
+	c.title,
+	count(distinct e.user_id) as unique_users,
+	count(distinct l.id) as lessons_count,
+	count(distinct lv.id) as total_views,
+	round(count(distinct lv.id)*1.0/nullif(count(distinct e.user_id), 0), 2) as avg_views_per_user,
+	min(lv.viewed_at) as first_viewed_at,
+	max(lv.viewed_at) as last_viewed_at
+from enrollments e
+join courses c on e.course_id = c.id
+join lessons l on  c.id = l.course_id
+join lessons_views lv on lv.lesson_id = l.id
+group by e.course_id, c.title
+order by e.course_id
diff --git a/mdrozdov/postgresql/dm_platform_summary.sql b/mdrozdov/postgresql/dm_platform_summary.sql
new file mode 100644
index 0000000..146fde7
--- /dev/null
+++ b/mdrozdov/postgresql/dm_platform_summary.sql
@@ -0,0 +1,8 @@
+create materialized view dm_platform_summary as
+select 
+	(select count(id) from users) as total_users,
+	(select count(id) from courses) as total_courses,
+	(select count(id) from lessons) as total_lessons,
+	(select count(distinct user_id) from lessons_views) as users_with_views,
+	round((select count(id) from lessons)*1.0/nullif((select count(id) from courses), 0), 2) as avg_lessons_per_course,
+	round((select count(id) from lessons_views)*1.0/nullif((select count(id) from lessons), 0), 2) as avg_views_per_lesson
\ No newline at end of file
diff --git a/mdrozdov/postgresql/dm_user_activity_summary.sql b/mdrozdov/postgresql/dm_user_activity_summary.sql
new file mode 100644
index 0000000..413d937
--- /dev/null
+++ b/mdrozdov/postgresql/dm_user_activity_summary.sql
@@ -0,0 +1,84 @@
+CREATE MATERIALIZED VIEW dm_user_activity_summary as 
+with enrollment_counts as(
+	select user_id, 
+		   count(course_id) as enrollment_count
+	from enrollments e
+	group by user_id
+),views as(
+	select user_id, 
+		count(distinct lesson_id) as viewed_lessons_count,
+		min(viewed_at) as first_view, 
+		max(viewed_at) as last_view
+	from lessons_views
+	group by user_id
+), total_lessons as(
+	select 	user_id, 
+			count(*) as total_lessons
+	from enrollments e
+	join lessons using(course_id)
+	group by user_id
+	order by user_id
+), engagment_rate as (
+	select tl.user_id, round(v.viewed_lessons_count*100.0/nullif(total_lessons), 2) as engagment_rate
+	from total_lessons tl
+	join views v using(user_id) 
+)
+select u.id, u.name, enrollment_count, viewed_lessons_count, last_view, first_view, engagment_rate
+from users u
+join enrollment_counts ec on u.id = ec.user_id
+join views v on u.id = v.user_id 
+join engagment_rate er on u.id = er.user_id
+order by u.id
+/*
+--первая попытка сделать витрину, делал избыточно с проверкой каждого подзапроса, поэтому забыл убрать order by, а также больше практиковался в оконных функциях
+CREATE MATERIALIZED VIEW user_activity_summary as
+with enrollment_counts as(
+	select distinct user_id, 
+		   count(course_id) over (partition by user_id) as enrollment_count
+	from enrollments e
+	order by user_id
+), viewed_lessons_count as (
+	select 
+			user_id, count(distinct lesson_id) as viewed_lessons_count
+	from lessons_views lv
+	group by user_id
+	order by user_id
+), first_views as(
+	select 
+			user_id,
+			viewed_at,
+			row_number() over (partition by user_id order by viewed_at asc) as rnf
+	from lessons_views
+), last_views as(
+	select 
+			user_id,
+			viewed_at,
+			row_number() over (partition by user_id order by viewed_at desc) as rnl
+	from lessons_views
+), result_views as(
+	select user_id, 
+		fw.viewed_at as first_view, 
+		lw.viewed_at as last_view
+	from first_views fw
+	join last_views lw using(user_id)
+	where rnf = 1 and rnl = 1
+), total_lessons as(
+	select 	user_id, 
+			count(*) as total_lessons
+	from enrollments e
+	join lessons using(course_id)
+	group by user_id
+	order by user_id
+), engagment_rate as (
+	select tl.user_id, round(vlc.viewed_lessons_count*100.0/total_lessons, 2) as engagment_rate
+	from total_lessons tl
+	join viewed_lessons_count vlc using(user_id) 
+)
+select u.id, u.name, enrollment_count, viewed_lessons_count, last_view, first_view, engagment_rate
+from users u
+join enrollment_counts ec on u.id = ec.user_id
+join viewed_lessons_count vlc on u.id = vlc.user_id
+join result_views rv on u.id = rv.user_id
+join engagment_rate er on u.id = er.user_id
+order by u.id
+*/
\ No newline at end of file