SQL Server 2019

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CREATE TABLE BASE_TABLE (
    ID int
    ,VALUE1 varchar(10)
    ,VALUE2 varchar(255)
) 
insert into BASE_TABLE VALUES
(1,'aa','aa'),
(2,'bb','bb'),
(3,'cc','cc'),
(4,'dd','dd'),
(5,'ee','ee'),
(6,'ff','ff'),
(7,'gg','gg'),
(8,'hh','hh'),
(9,'ii','ii')
9 rows affected

declare @part int = 3

;with baseRowNums as 
 (
   SELECT ID, VALUE1, VALUE2,
      Row_Number() Over (ORDER BY ID) AS rn
   FROM BASE_TABLE
 )
,batchNums as
(
SELECT *,
   Sum(CASE WHEN rn % @part = 1 THEN 1 ELSE 0 END)
   Over (ORDER BY ID, rn 
         ROWS Unbounded Preceding) AS part
FROM baseRowNums
)
,GUIDs as
(select part, MAX(newid()) as GUID
 from batchNums
 group by part
)
select ID, VALUE1, VALUE2, GUIDs.GUID
from batchNums
join GUIDs on batchNums.part = GUIDs.part


ID
VALUE1
VALUE2
GUID


1
aa
aa
41268bc9-4ee2-4a6b-8faa-b28c1b15fd96

2
bb
bb
41268bc9-4ee2-4a6b-8faa-b28c1b15fd96

3
cc
cc
41268bc9-4ee2-4a6b-8faa-b28c1b15fd96

4
dd
dd
e77c48ca-77ab-4c45-bb26-e14d96e9ad0c

5
ee
ee
e77c48ca-77ab-4c45-bb26-e14d96e9ad0c

6
ff
ff
e77c48ca-77ab-4c45-bb26-e14d96e9ad0c

7
gg
gg
c9b4cf53-cc50-4a8c-8497-947c02495181

8
hh
hh
c9b4cf53-cc50-4a8c-8497-947c02495181

9
ii
ii
c9b4cf53-cc50-4a8c-8497-947c02495181

ID	VALUE1	VALUE2	GUID
1	aa	aa	41268bc9-4ee2-4a6b-8faa-b28c1b15fd96
2	bb	bb	41268bc9-4ee2-4a6b-8faa-b28c1b15fd96
3	cc	cc	41268bc9-4ee2-4a6b-8faa-b28c1b15fd96
4	dd	dd	e77c48ca-77ab-4c45-bb26-e14d96e9ad0c
5	ee	ee	e77c48ca-77ab-4c45-bb26-e14d96e9ad0c
6	ff	ff	e77c48ca-77ab-4c45-bb26-e14d96e9ad0c
7	gg	gg	c9b4cf53-cc50-4a8c-8497-947c02495181
8	hh	hh	c9b4cf53-cc50-4a8c-8497-947c02495181
9	ii	ii	c9b4cf53-cc50-4a8c-8497-947c02495181