Best approach for data cleansing

Question

Hi Experts,
I have a database with more than 600+ tables. Some of the table are very big ranging from 50 to 60 GB in production. Tables are related to each other using foreign key (no ON DELETE CASCADE). I have been asked to remove data from all these tables where
PCode=10. Most of the tables have multiple indexes on it. I know, inner join delete operations, are going to be extremely resource intensive especially on our bigger tables. Guys, please do let me know what is the best practical approach (as per industry
standards) to remove these data from all the table at the least possible time.
Thanks in advance.
Regards,
Naveen
Naveen J V

Answer 1

Hi,
This can be usefull
http://stackoverflow.com/questions/159038/can-foreign-key-constraints-be-temporarily-disabled-using-t-sql
Declare @Sql NVarchar(Max), @Tables_Name NVarchar(100), @Columns_Name NVarchar(100),@obj_id bigint,@sql_cols NVarchar(Max),@sql_cols_4_upd NVarchar(max),@SQL_COUNT_MAX NVarchar(Max)
--SELECT * FROM sys.Columns
DECLARE tables_c CURSOR FOR
SELECT t.Name, t.Object_id FROM sys.Tables t
INNER JOIN sys.columns c on t.object_id = c.object_id
where c.name = 'PCode'
OPEN tables_c
FETCH NEXT FROM tables_c INTO @Tables_Name, @obj_id
IF @@FETCH_STATUS <> 0
PRINT ' <<None>>'
WHILE @@FETCH_STATUS = 0
BEGIN
SET @Sql = 'ALTER TABLE '+@Tables_Name+' NOCHECK CONSTRAINT all' + CHAR(10)
Set @Sql = @Sql +'DELETE'+ @Tables_Name + ' WHERE PCode = 10' + CHAR(10)
SET @Sql = @Sql + 'ALTER TABLE '+@Tables_Name+' CHECK CONSTRAINT all' + CHAR(10)
Print @Sql
--EXEC (@SQL)
FETCH NEXT FROM tables_c INTO @Tables_Name,@obj_id
END
CLOSE tables_c
DEALLOCATE tables_c