Исправился по всем замечаниям

bhabibullin/clickhouse/clickhouse_pet.sql

@@ -86,6 +86,8 @@ ORDER BY (lesson_id, course_id);
     - Дата первого и последнего просмотра
  */
 
+-- Основная таблица с AggregatingMergeTree
+
 CREATE TABLE bhabibullin.lesson_popularity_summary
 ON CLUSTER clickhouse_cluster
 (
@@ -93,18 +95,19 @@ ON CLUSTER clickhouse_cluster
     lesson_title  String,
     course_id     UInt32,
     course_title  String,
-    total_views   UInt32,
+    total_views   AggregateFunction(sum, UInt64),
-    unique_users  UInt32,
+    unique_users  AggregateFunction(uniq, UInt32),
-    first_view    DateTime64(3, 'UTC'),
+    first_view    AggregateFunction(min, DateTime64(3, 'UTC')),
-    last_view     DateTime64(3, 'UTC')
+    last_view     AggregateFunction(max, DateTime64(3, 'UTC'))
 )
-ENGINE = ReplicatedMergeTree(
+ENGINE = ReplicatedAggregatingMergeTree(
-	'/clickhouse/tables/{shard}/bhabibullin/lesson_popularity_summary',
+    '/clickhouse/tables/{shard}/bhabibullin/lesson_popularity_summary',
-	'{replica}'
+    '{replica}'
 )
-ORDER BY (lesson_id, course_id);
+ORDER BY (lesson_id, course_id)
+SETTINGS index_granularity = 8192;
 
-CREATE MATERIALIZED VIEW mv_lesson_popularity_summary
+CREATE MATERIALIZED VIEW bhabibullin.mv_lesson_popularity_summary
 ON CLUSTER clickhouse_cluster
 TO bhabibullin.lesson_popularity_summary
 AS
@@ -113,13 +116,13 @@ SELECT
     l.title AS lesson_title,
     flv.course_id AS course_id,
     c.title AS course_title,
-    count() AS total_views,
+    sumState(1) AS total_views,
-    uniqExact(flv.user_id) AS unique_users,
+    uniqState(flv.user_id) AS unique_users,
-    min(flv.viewed_at) AS first_view,
+    minState(flv.viewed_at) AS first_view,
-    max(flv.viewed_at) AS last_view
+    maxState(flv.viewed_at) AS last_view
 FROM core_fact_lesson_views AS flv
-JOIN core_dim_lesson  AS l ON flv.lesson_id = l.lesson_id
+JOIN core_dim_lesson AS l ON flv.lesson_id = l.lesson_id
-JOIN core_dim_course  AS c ON flv.course_id = c.course_id
+JOIN core_dim_course AS c ON flv.course_id = c.course_id
 GROUP BY
     flv.lesson_id,
     l.title,
@@ -189,21 +192,24 @@ ORDER BY user_id;
 
 CREATE MATERIALIZED VIEW bhabibullin.mv_inactive_users_summary 
 ON CLUSTER clickhouse_cluster
-to bhabibullin.inactive_users_summary 
+TO bhabibullin.inactive_users_summary 
 AS
 SELECT  
     cdu.user_id,
     cdu.name,
     cdu.email,
     cdu.age,
-    0 as enrollment_count,
+    countDistinct(flv.course_id) as enrollment_count,
     cdu.registration_date
 FROM core_dim_user cdu 
-WHERE (cdu.user_id, 1) NOT IN (
+LEFT ANTI JOIN core_fact_lesson_views flv 
-    SELECT user_id, 1 
+    ON cdu.user_id = flv.user_id
-    FROM core_enrollments
+GROUP BY 
-    GROUP BY user_id
+    cdu.user_id,
-);
+    cdu.name,
+    cdu.email,
+    cdu.age,
+    cdu.registration_date;
 
 INSERT INTO bhabibullin.inactive_users_summary
 SELECT  

bhabibullin/greenplum/pet_project_gp.sql

@@ -119,16 +119,14 @@ SELECT
     dl.title AS lesson_title,
     dc.course_id,
     dc.title AS course_title,
-    COUNT(flv.lesson_id) AS total_views,
+    COUNT(*) AS total_views,
-    COUNT(DISTINCT du.user_id) AS unique_users,
+    COUNT(DISTINCT flv.user_id) AS unique_users,
     MIN(flv.viewed_at) AS first_view,
     MAX(flv.viewed_at) AS last_view
 FROM core.dim_lesson dl
 JOIN core.dim_course dc ON dc.course_id = dl.course_id
 JOIN core.fact_lesson_views flv ON flv.lesson_id = dl.lesson_id
-JOIN core.dim_user du ON du.user_id = flv.user_id
+GROUP BY dl.lesson_id, dl.title, dc.course_id, dc.title;
-GROUP BY dl.lesson_id, dl.title, dc.course_id, dc.title
-ORDER BY dl.lesson_id;
 
 
 /*
@@ -155,12 +153,15 @@ SELECT
     du.name AS user_name,
     du.email,
     du.age,
-    COUNT(e.course_id) AS enrollments_count,
+    COUNT(DISTINCT e.course_id) AS enrollments_count,
     du.registration_date
 FROM core.dim_user du
 LEFT JOIN core.enrollments e ON e.user_id = du.user_id
-LEFT JOIN core.fact_lesson_views flv ON flv.user_id = du.user_id
+WHERE NOT EXISTS (
-WHERE flv.user_id IS NULL
+    SELECT 1 
+    FROM core.fact_lesson_views flv 
+    WHERE flv.user_id = du.user_id
+)
 GROUP BY du.user_id, du.name, du.email, du.age, du.registration_date;
 
 /*

bhabibullin/postgre/postrge_pet_project.sql

@@ -90,12 +90,10 @@ select
 	count(distinct lv.lesson_id) as viewed_lessons_count,
 	max(lv.viewed_at) as last_view,
 	min(lv.viewed_at) as first_view,
-	round(
+    round(count(distinct lv.lesson_id) * 100.0 / NULLIF(al.cnt_lesson, 0), 4) as engagement_rate
-		count(distinct lv.lesson_id) * 100.0 / al.cnt_lesson
-	,2) || '%' as engagegement_rate
 from users u
 join enrollments e on u.id = e.user_id 
-join lesson_views lv on lv.user_id = u.id 
+left join lesson_views lv on lv.user_id = u.id 
 join available_lessons al on al.user_id = u.id 
 group by u.id, u.name, al.cnt_lesson
 );
@@ -136,7 +134,7 @@ from
 	join lessons l on c.id = l.course_id
 	join enrollments e on e.course_id = c.id 
 	join view_cnt vc on vc.course_id = c.id 
-	join lesson_views lv on lv.lesson_id = l.id
+	left join lesson_views lv on lv.lesson_id = l.id
 group by c.title, vc.cnt, c.id 
 order by course_id
 );
@@ -162,8 +160,8 @@ select
 	count(distinct c.id) as total_courses,
 	count(distinct l.id) as total_lessons,
 	count(distinct lv.user_id) as users_with_views,
-	round(count(distinct l.id) * 1.0 / count(distinct c.id), 2) as avg_lessons_per_course,
+	round(count(distinct l.id) * 1.0 / NULLIF(count(distinct c.id), 0), 2) as avg_lessons_per_course,
-	count(lv.lesson_id) * 1.0 / count(distinct l.id)  as avg_lessons_per_lesson
+	count(lv.lesson_id) * 1.0 / NULLIF(count(distinct l.id), 0) as avg_lessons_per_lesson
 from users u
 left join lesson_views lv on lv.user_id = u.id
 left join lessons l on l.id = lv.lesson_id