Question

I have this sql update statement which updates a remote table. Is there any way I can optimize/speed up this code? It is running as part of a stored procedure.

DECLARE @WIP Table(Item varchar(25), WIP int)

--Get Work In Progress Numbers
INSERT INTO @WIP
select (UPC.ItemPrefix + '-' + UPC.ItemCode) As Item, SUM(PO.Quantity) As WIP
--into #WIP
from [NCLGS].[dbo].[AL_ItemUPCs] UPC
INNER JOIN al_PO PO ON PO.UPCID = UPC.UPCID
where PO.status in ('Assigned', 'New', 'UnAssigned', 'WaitingForFile')
Group by  (UPC.ItemPrefix + '-' + UPC.ItemCode)

--SLOW PART, takes over 17 minutes
UPDATE [Server].[Database].[dbo].[Item]  
SET     QtyOnHand = IH.QtyOnHand,
        QtyWorkInProgress = W.WIP   
FROM Avanti_InventoryHeader IH
INNER JOIN [Server].[Database].[dbo].[Item] I ON I.ItemNumber = IH.ItemNumber
LEFT JOIN @WIP W ON IH.ItemNumber = W.Item
WHERE isnumeric(left(IH.ItemNumber, 2)) = 0

Answer 1

I figured out the real problem with the query, it was updating thousands of records, even if those records didn’t change. So I queried for the changed records, saved that in a table variable, and only updated the changed records. Entire procedure (not just this part) went from 16min 44sec to 1min 26 sec.

--BEGIN EXPERIMENTAL ITEM UPDATE SECTION
    DECLARE @WIP Table(Item varchar(25), WIP int)

    --Get Work In Progress Numbers
    INSERT INTO @WIP
    select (UPC.ItemPrefix + '-' + UPC.ItemCode) As Item, SUM(PO.Quantity) As WIP
    --into #WIP
    from [NCLGS].[dbo].[AL_ItemUPCs] UPC
    INNER JOIN al_PO PO ON PO.UPCID = UPC.UPCID
    where PO.status in ('Assigned', 'New', 'UnAssigned', 'WaitingForFile')
    Group by  (UPC.ItemPrefix + '-' + UPC.ItemCode)

    Declare @Remote Table(Item varchar(25), QtyOnHand int, WIP int)

    INSERT INTO @REMOTE
    Select ItemNumber, QtyOnHand, QtyWorkInProgress
    from [BMPR.COM].[NCL-CustomerPortal].[dbo].[Item]

    DECLARE @ItemsToUpdate Table (Item varchar(50))

    INSERT INTO @ItemsToUpdate
    Select R.Item
    From @Remote R
    Inner join Avanti_InventoryHeader IH ON R.Item = IH.ItemNumber
    LEFT JOIN @WIP W ON R.Item = W.Item
    Where R.QtyOnHand <> IH.QtyOnHand 
    OR R.WIP <> W.WIP

    --Select * from @ItemsToUpdate

    UPDATE [BMPR.COM].[NCL-CustomerPortal].[dbo].[Item]  
    SET     QtyOnHand = IH.QtyOnHand,
            QtyWorkInProgress = W.WIP   
    FROM Avanti_InventoryHeader IH
    INNER JOIN [BMPR.COM].[NCL-CustomerPortal].[dbo].[Item] I ON I.ItemNumber = IH.ItemNumber
    LEFT JOIN @WIP W ON IH.ItemNumber = W.Item
    WHERE I.ItemNumber in ( Select * from @ItemsToUpdate )
--END EXPERIMENTAL ITEM UPDATE SECTION

Any comments on this method?