Tuning Stored Procedure - sql-server

Question

How can you improve this without using a cursor? I was thinking using table variable would help, but am I going right direction doing so? I have omitted cursor and try to do it with table variable. Please help, here is the code.
IF EXISTS (SELECT * FROM sysobjects WHERE id = object_id(N'[dbo].[BatchProcessBridge_CustomerEvent]') AND [xtype] IN (N'P'))
BEGIN
DROP PROCEDURE [dbo].[BatchProcessBridge_CustomerEvent]
END
GO
CREATE PROCEDURE [dbo].[BatchProcessBridge_CustomerEvent]
(
#BatchJobTable Bridge_CustomerEventBatchJobTable READONLY,
#Name VARCHAR(50)
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #Lsn BINARY(10),
DECLARE #SeqVal BINARY(10),
DECLARE #Action VARCHAR(300),
DECLARE #CustId VARCHAR(MAX)
--using tabel variable. Cursor gives bad performance.
DECLARE #TEMP_TABLE TABLE ( [Lsn] BINARY(10), [SeqVal] BINARY(10), [Action] VARCHAR(300), [CustId] VARCHAR(MAX))
INSERT INTO #TEMP_TABLE
SELECT Lsn, SeqVal, [Action], [CustId] FROM #BatchJobTable
--DECLARE GetBatchJobCursor CURSOR FAST_FORWARD
--FOR
--SELECT Lsn, SeqVal, [Action], [CustId] FROM #BatchJobTable
--OPEN GetBatchJobCursor
--FETCH NEXT FROM GetBatchJobCursor INTO #Lsn, #SeqVal, #Action, #CustId
--WHILE ##FETCH_STATUS = 0
BEGIN
BEGIN TRY
BEGIN TRANSACTION
IF (#Action = 'create')
BEGIN
-- Create.
INSERT INTO [Bridge_Customer]
(
[CustId]
,[PersonId]
,[DisplayName]
,[CreatedDate]
,[ModifiedDate]
)
SELECT
[CustId]
,[PersonId]
,[DisplayName]
,[CreatedDate]
,[ModifiedDate]
FROM
#BatchJobTable
WHERE
(Lsn = #Lsn) AND (SeqVal = #SeqVal)
END
ELSE IF (#Action = 'update')
BEGIN
-- Update.
UPDATE [Target]
SET
[Target].[CustId] = [Ref].[CustId]
,[Target].[PersonId] = [Ref].[PersonId]
,[Target].[DisplayName] = [Ref].[DisplayName]
,[Target].[CreatedDate] = [Ref].[CreatedDate]
,[Target].[ModifiedDate] = [Ref].[ModifiedDate]
FROM
[dbo].[Bridge_Customer] AS [Target]
INNER JOIN
(SELECT * FROM #BatchJobTable WHERE (Lsn = #Lsn) AND (SeqVal = #SeqVal)) AS [Ref]
ON
([Target].[CustId] = [Ref].[CustId])
END
ELSE IF (#Action = 'delete')
BEGIN
DELETE FROM [dbo].[Bridge_Customer] WHERE [CustId] = #CustId
END
-- Update last processed event.
EXEC [dbo].[UpdateLastProcessedEvent]
#Name = #Name,
#Lsn = #Lsn,
#SeqVal = #SeqVal
COMMIT TRANSACTION
END TRY
BEGIN CATCH
DECLARE #ErrorMessage NVARCHAR(4000);
DECLARE #ErrorSeverity INT;
DECLARE #ErrorState INT;
SELECT
#ErrorMessage = ERROR_MESSAGE(),
#ErrorSeverity = ERROR_SEVERITY(),
#ErrorState = ERROR_STATE();
-- Use RAISERROR inside the CATCH block to return error
-- information about the original error that caused
-- execution to jump to the CATCH block.
RAISERROR (#ErrorMessage, -- Message text.
#ErrorSeverity, -- Severity.
#ErrorState -- State.
);
ROLLBACK TRANSACTION
END CATCH
--FETCH NEXT FROM GetBatchJobCursor INTO #Lsn, #SeqVal, #Action, #CustId
END
--CLOSE GetBatchJobCursor
--DEALLOCATE GetBatchJobCursor
END
GO

Answer 1

A cursor is not necessary here; this is just basic SQL. Forgive any mistakes with my code as you haven't provided any DLL but I'm pretty sure you can just do this:
IF (#Action = 'create')
INSERT INTO Bridge_Customer
(
CustId
,PersonId
,DisplayName
,CreatedDate
,ModifiedDate
)
SELECT
CustId
,PersonId
,DisplayName
,CreatedDate
,ModifiedDate
FROM #BatchJobTable
ELSE IF (#Action = 'update')
UPDATE tgt
SET tgt.CustId = Ref.CustId
,tgt.PersonId = Ref.PersonId
,tgt.DisplayName = Ref.DisplayName
,tgt.CreatedDate = Ref.CreatedDate
,tgt.ModifiedDate = Ref.ModifiedDate
FROM dbo.Bridge_Customer AS tgt
INNER JOIN #BatchJobTable AS ref
ON (tgt.CustId = Ref.CustId)
ELSE IF (#Action = 'delete')
DELETE FROM dbo.Bridge_Customer
WHERE CustId IN (SELECT CustId FROM #BatchJobTable);
Personally, I would split this into three stored and call whichever one from the application layer. What you are doing is known as a "Catch All query" which is fine but, if you must go that route, read this: Catch All Queries (Gail Shaw)