Hi All,

I am supporting a Forecasting WinForms application written in VB.NET with the SQL Server 2005 back end. At least once a day users are complaining about time out error. When I check the activity monitor I always see a process id responsible for blocking other processes with the wait type = ASYNC_NETWORK_IO. When I run the DBCC INPUTBUFFER(ID) it always returns the same select statement:

select AlertFlg as Alert, Status as St, PageNo, Warehouse_Pref as Whse, 
	ItemMst.ProdFam, PItems.Itemno as SKU, Description, QoH, TotalDue as Due, 
	NJBuyQty,NJPurchQty as NJBought, NVBuyQty, NVPurchQty as NVBought, NextPODate, 
	ProdType.Descpt as Type, History.NJUseable as NJQOH, History.NVUseable as NVQOH, 
	pitems.BO, DueNJ as NJDue, DueNV as RenoDue, AvailInv as Avail, DemCanL as L, 
	DemCan4 as '4', DemCan8 as '8', R13, history.DemCan13 as '13', DemCan26 as '26', 
	DemCan52 as '52', ListPrice as List, PVC, SVC, isnull(acostrec, 0) as LCP, 
	amswebprice as AMSWeb, amscatprice as AMSCat, zzsellprice as zZounds, 
	sdmprice as SameDay, amzamsprice as AMSAmazSell, amzzzprice as zZAmazSell, 
	PV, PVB as PVDate, SVB as SVDate, SV, PVItemNo as PVSKU, UPCNo, RSSku, AmsEmp, 
	zZ1, zZ2, SD1, SD2, OverSzd, ExclPH, ExtraPH, PO1, PO1Date, PO1Qty, PO2, 
	PO2Date, PO2Qty, PO3, PO3Date, PO3Qty, PO4, PO4Date, PO4Qty, 
	targetprice as Target, WirelessFlg as Wireless, BuyInCase, CaseQty, pitems.EDPNO 
from itemmst, history, forecast, poffers, prodtype, VendorMst, pitems 
full outer join plastpo on pitems.edpno = plastpo.edpno 
where pitems.edpno = itemmst.edpno 
and pitems.edpno = history.edpno 
and prodtype.codno = itemmst.prodtype  
and pitems.edpno = forecast.edpno 
and pitems.edpno = poffers.edpno 
and PV = VendorMst.VendNo 
and pitems.pvb = 'Mike' 

I made sure that all indexes are in place and query execution time is around 2-3 seconds.

Can anyone recommend how to further tune this query and what the ASYNC_NETWOR_IO wait type indicates?

TIA,
DAniel