Database

COL1    COL2    COL3
X       100	  1
X       200	  2
X       300	  3
Y       100	  1
Y       200	  2
Z       300	  1

A    B
1    100
1    200
1    300
2    100
2    200
3    100

/****** Object:  Table [dbo].[EXP_REL_SLOT_DOMN]    Script Date: 06/04/2009 08:38:19 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[EXP_REL_SLOT_DOMN](
	[SLOT] [int] NOT NULL,
	[DOMN] [int] NOT NULL,
	[PREF] [int] NOT NULL
) ON [PRIMARY]

GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'references TBL_SLOT_ALLC.ID' ,@level0type=N'SCHEMA', @level0name=N'dbo', @level1type=N'TABLE', @level1name=N'EXP_REL_SLOT_DOMN', @level2type=N'COLUMN', @level2name=N'SLOT'

/****** Object:  Index [EXP_REL_SLOT_DOMN_INDEX]    Script Date: 06/04/2009 08:41:01 ******/
CREATE UNIQUE CLUSTERED INDEX [EXP_REL_SLOT_DOMN_INDEX] ON [dbo].[EXP_REL_SLOT_DOMN] 
(
	[SLOT] ASC,
	[DOMN] ASC,
	[PREF] ASC
)WITH (SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, IGNORE_DUP_KEY = ON, ONLINE = OFF) ON [PRIMARY]

--29 seconds
INSERT into tempslot
select distinct sd1.slot as s1, sd2.slot as s2
from [dbo].[EXP_REL_SLOT_DOMN] sd1
inner join [dbo].[EXP_REL_SLOT_DOMN] sd2
on sd1.domn = sd2.domn 
and sd1.slot > sd2.slot

--29 seconds
INSERT into tempslot
select distinct sd1.slot as s1, sd2.slot as s2
from [dbo].[EXP_REL_SLOT_DOMN] sd1
inner join [dbo].[EXP_REL_SLOT_DOMN] sd2
on sd1.domn = sd2.domn 
and sd1.slot < sd2.slot

exec sp_configure 'clr enabled',1 --enable sql to execute CLR
reconfigure --install and run it
go
alter database TestTrigger set trustworthy on --enable Database to access external files
go
use TestTrigger
go
drop assembly WriteToFile
go
declare @dllPath varchar(500)
set @dllPath='C:\Documents and Settings\a.hamidy\My Documents\SharpDevelop Projects\WriteToFile\WriteToFile\bin\Debug\WriteToFile.dll'
create assembly WriteToFile from @dllPath with permission_set = external_access --create assembly from following dll file
go
--now create store procedure to access that dll file class + methods
create proc dbo.writeToFile
(
	@filePath varchar(500),
	@fileContent varchar(max)
)
as external name [WriteToFile].[WriteToFile].[writeInFile]