--page_views table
	create table page_views (
		user_id UInt64,
		url  String,
		view_time DateTime
	)
	Engine = MergeTree
	Order by (user_id, view_time)
	Partition by toYYYYMM(view_time)
	
	-- users table
	create table users(
		id UInt64,
		name String,
		updated_at DateTime
	)
	ENGINE = ReplacingMergeTree(updated_at)
	Order by id;
	
	-- region_sales table
	create table mdrozdov.region_sales(
		region String,
		date Date,
		sales UInt64
	)
	ENGINE = SummingMergeTree
	Partition by toYYYYMM(date)
	Order by (region, date)
	
	insert into mdrozdov.region_sales (region, date, sales)
	values ('Russia', '2025-01-14', 30), ('Russia', '2025-01-16', 22), ('USA', '2025-01-14', 1400)
	OPTIMIZE TABLE mdrozdov.region_sales FINAL
	
	-- user_metrics table
	create table mdrozdov.user_metrics (
		region String,
		avg_age_state AggregateFunction(avg, UInt8),
		active_users_state AggregateFunction(uniq, UInt64)
	)
	Engine = AggregatingMergeTree
	Order by region
	
	INSERT INTO mdrozdov.user_metrics
	SELECT
	    'Moscow' AS region,
	    avgState(toUInt8(25)) AS avg_age_state,
	    uniqState(toUInt64(100)) AS active_users_state
	UNION ALL
	SELECT
	    'Moscow',
	    avgState(toUInt8(30)),
	    uniqState(toUInt64(50))
	UNION ALL
	SELECT
	    'SPB',
	    avgState(toUInt8(20)),
	    uniqState(toUInt64(10));
	
	SELECT
	    region,
	    avgMerge(avg_age_state) AS avg_age,
	    uniqMerge(active_users_state) AS active_users
	FROM mdrozdov.user_metrics
	GROUP BY region