Delete large table in batch with join




 /***************************************
  if object_id('Table1','U') is not null
  drop table Table1 ;

  create table Table1 ( id int, filename varchar(50));

  if object_id('Table2','U') is not null
  drop table Table2 ;
create table Table2 ( id int, filename varchar(50), FILE_DESC  varchar(50) , [Processed_date] datetime)

--drop table table1, table2
truncate table table1
truncate table table2

insert into Table1 values (1,'a1'),(2,'a2'), (3,'a3'),(4,'a4'), (5,'a5'),(6,'a6'), (7,'a7'),(8,'a8'), (9,'a9'),(10,'a10'),
(11,'a11'),(12,'a12'), (13,'a13'),(14,'a14'), (15,'a5'),(16,'a16'), (17,'a17'),(18,'a18'), (19,'a19'),(20,'a20')

insert into Table2 values (1,'a1', 'EDI', '1/1/2000' ),(2,'a2', 'EDI', '1/1/2000'), (3,'a3', 'EDI', '1/1/2000'),(4,'a4', 'EDI', '1/1/2000'), (5,'a5', 'EDI', '1/1/2000')
,(6,'a6', 'EDI', '1/1/2000'), (7,'a7', 'EDI', '1/1/2000'),(8,'a8', 'EDI', '1/1/2000'), (9,'a9', 'EDI', '1/1/2000'),(10,'a10', 'EDI', '1/1/2000'),
(11,'a11', 'EDI', '1/1/2000'),(12,'a12', 'EDI', '1/1/2000'), (13,'a13', 'EDI', '1/1/2000'),(14,'a14', 'EDI', '1/1/2000'), (15,'a5', 'EDI', '1/1/2000')
,(16,'a16', 'EDI', '1/1/2000'), (17,'a17', 'EDI', '1/1/2000'),(18,'a18', 'EDI', '1/1/2000'), (19,'a19', 'EDI', '1/1/2000'),(20,'a20', 'EDI', '1/1/2000')


select * from table1
select * from table2


 ***************************************/


declare @Chunk int=5,  @ToBeDeleted int = 1
  
WHILE @ToBeDeleted > 0
  BEGIN
      BEGIN TRAN

	  ;with mycte as (
	  select row_number() Over(Order by b.[Processed_date]) rn ,a.filename
	  FROM Table1 a
INNER JOIN Table2 b ON a.filename = b.filename
WHERE  b.FILE_DESC = 'EDI'
AND b.[Processed_date] < DATEADD (WEEK, -10, Getdate ()) )
 
      DELETE  Table1
	  From Table1 a
	  inner join mycte m On a.filename = m.filename
	  Where  rn< @Chunk 

 
 
      SET @ToBeDeleted = @@ROWCOUNT
 
      PRINT 'Deleted rows: ' + Cast(@ToBeDeleted AS VARCHAR(10))
 
      COMMIT TRAN
  END





 
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