batches over groups, Sql Server

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DECLARE @test01 AS TABLE (
	  id INT PRIMARY KEY CLUSTERED IDENTITY(1, 1) NOT NULL
	, person_name NVARCHAR(100)
	, person_surname NVARCHAR(100)
	, person_group_code CHAR(2) NOT NULL
);

INSERT INTO @test01 (person_name, person_surname, person_group_code)
VALUES ('n1', 's1', 'g1')
, ('n2', 's2', 'g1')
, ('n3', 's3', 'g1')
, ('n4', 's4', 'g1')
, ('n5', 's5', 'g2')
, ('n6', 's6', 'g2')
, ('n7', 's7', 'g2')
, ('n8', 's8', 'g2')
, ('n9', 's9', 'g2')
, ('n10', 's10', 'g2')
, ('n11', 's11', 'g3')
, ('n12', 's12', 'g3')
, ('n13', 's13', 'g3')
, ('n14', 's14', 'g3');

DECLARE @batch_min_size int = 10
	  , @batch_end int = 0
      , @batch_start int
	  , @first_id_of_batch int
	  , @last_id_of_batch int
	  , @total_row_count int;

SELECT @total_row_count = COUNT(*) FROM @test01

DECLARE @Helper As Table (Id int, Rn int, GroupId int)
INSERT INTO @Helper (Id, Rn, GroupId)
SELECT  Id, 
		ROW_NUMBER() OVER(ORDER BY ID) As Rn,
		ROW_NUMBER() OVER(ORDER BY ID) -
		ROW_NUMBER() OVER(PARTITION BY person_group_code ORDER BY ID) As GroupId		
FROM @test01

WHILE @batch_end < @total_row_count 
BEGIN

SELECT @batch_start = @batch_end + 1;

SELECT @batch_end = MAX(Rn)
		 , @first_id_of_batch = MIN(Id)
		 , @last_id_of_batch = MAX(Id) 
	FROM @Helper 
	WHERE Rn >= @batch_start 
	AND GroupId <= 
	(
		SELECT MAX(GroupId)
		FROM @Helper
		WHERE Rn <= @batch_start + @batch_min_size - 1
	)

SELECT id, person_name, person_surname, person_group_code
	FROM @test01 
	WHERE Id >= @first_id_of_batch 
	AND Id <= @last_id_of_batch 
		
END

View schema
Execution time: 0,03 sec, rows selected: 20, rows affected: 28, absolute service time: 0,22 sec, absolute service time: 0,22 sec