How can I increase the efficiency of this MSSQL Stored Procedure? - sql-server

Question

I am working with some communications and returning data to a PLC, and executing a stored procedure often.
I was wondering if I could get an opinion on how I might be able to increase the efficiency of this stored procedure?
As of now, it runs roughly ~1600 or so times a day, which is fine. But moving forward, it's likely to run upwards of 5000 or some times a day. I was wondering what might be the best method to reduce the number of SELECT statements, is it possible I can use a CASE statement?
Below is some of the example code.
#machine nvarchar(25),
#suppliercode nvarchar(1),
#barcode nvarchar(16),
#sqlpass int OUTPUT,
#sqlfail int OUTPUT,
#output int OUTPUT,
#lotnomatch int OUTPUT,
#partnomatch int OUTPUT,
#foundlot nvarchar(16) OUTPUT
AS
BEGIN
SET #output = (SELECT COUNT(ID) FROM dbo.MCData WHERE Barcode = #barcode AND Machine = #machine)
IF (#output >= 1)
BEGIN
SET #sqlpass = 1
UPDATE dbo.MCBarcodeData SET Interfaced = 1, InterfacedDatetime = GetDate(), InterfacedMachine = #machine WHERE Barcode = #barcode AND Machine = #machine
END
IF (#output = 0)
BEGIN
SET #lotnomatch = (SELECT COUNT(ID) FROM dbo.MCData WHERE Barcode = #barcode AND Machine != #machine)
END
IF (#lotnomatch = 1)
BEGIN
SET #foundlot = (SELECT Machine FROM dbo.MCData WHERE Barcode = #Barcode)
END
IF (#output = 0 AND #lotnomatch = 0)
BEGIN
SET #partnomatch = 1
END
END
GO
Edit: Attached if the Query Execution Plan

Answer 1

Calculating statistics from a whole picture perspective on a regular basis always gets worse over time with more and more data. If it is something that isn't done very often then it isn't so bad, but if your doing it very often then it will hurt in the long run.
What I like to do is maintain the statistics as data is modified in a separate table.
For example, you might want a separate table that has a composite primary key of barcode and machine and then have a column for number of records in mcdata that match your key and number of records in mcdata that have the same barcode but not the same machine. You can also have a column for the machine name for the one that doesn't match if there is one.
CREATE TABLE MCDataStats
(
Barcode nvarchar(16),
Machine nvarchar(25),
NumMatchBarcodeMachineInMCData int,
NumMatchBarcodeNotMachineInMCData int,
LotMachineName nvarchar(25),
PRIMARY KEY (Barcode, Machine)
)
Then you could just run a single simple select on that statistics table.
CREATE PROCEDURE procMCDataStats_GET
#Barcode nvarchar(16),
#Machine nvarchar(25)
AS
BEGIN
SELECT *
FROM MCDataStats
WHERE Barcode = #Barcode AND
Machine = #Machine
END
To maintain the statistics you would update them as data is modified. Like in your stored procedure to add a record to mcdata. You would then insert a record in your statistics table for that barcode and machine you don't have it already. Then you would increment the number of records in mcdata column and then increment the number of records in mcdata that have same barcode but not the same machine for records in your statistics table with that barcode, but not the same machine. If you incremented any records in statistics table with that barcode, but not the same machine then you can verify the stats that are there to determine if you want to populate the lot column. And if you remove any records, make sure you go through and decrement.
CREATE PROCEDURE procMCData_ADD
#Barcode nvarchar(16),
#Machine nvarchar(25)
AS
BEGIN
INSERT INTO MCData (Barcode, Machine, ...)
VALUES (#Barcode, #Machine, ...)
--Insert into MCDataStats if barcode and machine don't exist
INSERT INTO MCDataStats (Barcode, Machine, NumMatchBarcodeMachineInMCData,
NumMatchBarcodeNotMachineInMCData)
SELECT #Barcode, #Machine, 0, 0
WHERE NOT EXISTS (SELECT TOP 1 * FROM MCDataStats WHERE Barcode = #Barcode AND Machine = #Machine)
UPDATE data
SET Interfaced = 1, InterfacedDatatime = GETDATE(), InterfacedMachine = #Machine
FROM MCDataStats AS stats
LEFT JOIN MCBarcodeData AS data ON data.Barcode = stats.Barcode AND data.Machine = stats.Machine AND stats.NumMatchBarcodeMachineInMCData = 1
--Update stats for matching barcode and machine
UPDATE stats
SET NumMatchBarcodeMachineInMCData = NumMatchBarcodeMachineInMCData + 1
FROM MCDataStats AS stats
WHERE Barcode = #Barcode AND Machine = #Machine
--Update stats for matching barcode but not machine
UPDATE stats
SET NumMatchBarcodeNotMachineInMCData = NumMatchBarcodeNotMachineInMCData + 1,
LotMachineName = (CASE WHEN NumMatchBarcodeMachineInMCData = 0 AND NumMatchBarcodeNotMachineInMCData = 0 THEN #Machine ELSE NULL END)
FROM MCDataStats AS stats
WHERE Barcode = #Barcode AND Machine <> #Machine
END

Answer 2

In my opinion you should consider to add non-clustered index in your tables.
For example:
CREATE NONCLUSTERED INDEX IX_MCData_Barcode_Machine
ON dbo.MCData (Barcode ASC, Machine ASC)
GO
CREATE NONCLUSTERED INDEX IX_MCBarcodeData_BarcodeMachine
ON dbo.MCBarcodeData (Barcode ASC, Machine ASC)
INCLUDE (Interfaced, InterfacedDatetime, InterfacedMachine)
GO