Delete From Vs Delete With Subquery In Transaction

First, this is not my code.

This one is weird and I am missing something fundamental on this one. A developer was getting a timeout with this...


CREATE PROCEDURE p_CM_DeleteBatch
(
@SubmitterTranID VARCHAR(50)
)
AS
DECLARE
@COUNT INT,
@COMMIT INT

SET @COUNT = 0
SET @COMMIT = 1 --DO NOT CHANGE THIS. The Operation will be commited only when this value is 1

select @COUNT = COUNT(*) from claimsreceived
where (claimstatus NOT IN ('Keyed', 'Imported')) AND
SubmitterTranID = @SubmitterTranID

IF (@COUNT = 0) --This means that that Claims under this Batch have not been adjudicated & it is safe to delete
BEGIN
BEGIN TRANSACTION
DELETE FROM INVOICECLAIMMAPPING WHERE CLMRECDID IN (SELECT DISTINCT CLMRECDID FROM CLAIMSRECEIVED WHERE SUBMITTERTRANID = @SUBMITTERTRANID)
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsPayment WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsPaymentServices WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsreceivedPayorServices where ClmRecdPyID in (SELECT ClmRecdPyID
FROM ClaimsReceivedPayors
WHERE SubmitterTranID = @SubmitterTranID)

IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsReceivedPayors WHERE ClmRecdid in (SELECT ClmRecdID
FROM ClaimsReceived
WHERE SubmitterTranID = @SubmitterTranID)
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsReceivedServices WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0
DELETE FROM ClaimsReceived WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0
DELETE FROM BATCHLOGCLAIMS WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

IF (@COMMIT = 1)
BEGIN
--ROLLBACK TRANSACTION --For Testing Purpose ONLY
COMMIT TRANSACTION
RETURN (0)
END
ELSE
BEGIN
ROLLBACK TRANSACTION
RETURN (-1)
END
END
ELSE
BEGIN
RaisError ('This Batch cannot be deleted. It has claim(s) which has been Adjudicated', 16, 1)
END
GO


I applied a couple of indices and got ride of the uncorrelated subqueries


CREATE PROCEDURE p_CM_DeleteBatch
(
@SubmitterTranID VARCHAR(50)
)
AS
DECLARE
@COUNT INT,
@COMMIT INT

SET @COUNT = 0
SET @COMMIT = 1 --DO NOT CHANGE THIS. The Operation will be commited only when this value is 1

select @COUNT = COUNT(*) from claimsreceived
where (claimstatus NOT IN ('Keyed', 'Imported')) AND
SubmitterTranID = @SubmitterTranID

IF (@COUNT = 0) --This means that that Claims under this Batch have not been adjudicated & it is safe to delete
BEGIN
BEGIN TRANSACTION

DELETE INVOICECLAIMMAPPING
FROM INVOICECLAIMMAPPING
JOIN CLAIMSRECEIVED
ON INVOICECLAIMMAPPING.CLMRECDID = CLAIMSRECEIVED.CLMRECDID
WHERE CLAIMSRECEIVED.SUBMITTERTRANID = @SUBMITTERTRANID

IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsPayment
WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsPaymentServices WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE ClaimsreceivedPayorServices
FROM ClaimsreceivedPayorServices
JOIN ClaimsReceivedPayors
ON ClaimsreceivedPayorServices.ClmRecdPyID = ClaimsReceivedPayors.ClmRecPyID
WHERE ClaimsReceivedPayors.SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE ClaimsReceivedPayors
FROM ClaimsReceivedPayors
JOIN ClaimsReceived
ON ClaimsReceivedPayors.ClmRecdid = ClaimsReceived.ClmRecdid
WHERE ClaimsReceived.SubmitterTranID = @SubmitterTranID

IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsReceivedServices WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM ClaimsReceived WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

DELETE FROM BATCHLOGCLAIMS WHERE SubmitterTranID = @SubmitterTranID
IF (@@ERROR <> 0)
SET @COMMIT = 0

IF (@COMMIT = 1)
BEGIN
--ROLLBACK TRANSACTION --For Testing Purpose ONLY
COMMIT TRANSACTION
RETURN (0)
END
ELSE
BEGIN
ROLLBACK TRANSACTION
RETURN (-1)
END
END
ELSE
BEGIN
RaisError ('This Batch cannot be deleted. It has claim(s) which has been Adjudicated', 16, 1)
END
GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON

GO


Suddenly this constraint was being violated with the change


ALTER TABLE [dbo].[ClaimsReceivedPayorServices] ADD CONSTRAINT [FK_ClaimsReceivedPayorServices_CLAIMSRECEIVEDPAYOR S] FOREIGN KEY
(
[ClmRecdPyID]
) REFERENCES [CLAIMSRECEIVEDPAYORS] (
[CLMRECPYID]
)


Is the delete on ClaimsReceivedPayors starting before the delete on ClaimsreceivedPayorServices finishes? If so why would it matter between the join and subquery? This one is making me depressed because I can not explain it.