提高连接14个表的SQL查询的性能

Question

I am trying to join 14 tables in which few tables I need to join using left join. With the existing data which is around 7000 records,its taking around 10 seconds to execute the below query.I am afraid what if the records are more than million.Please help me improve the performance of the below query.

CREATE proc [dbo].[GetTodaysActualInvoiceItemSoldHistory]                          
@fromdate datetime,        
@todate datetime        
as                          

Begin                    

select SDID.InvoiceDate as [Sold Date],Cust.custCompanyName as [Sold To] ,   
case SQBD.TransferNo  when '0' then IVM.VendorName else SQBD.TransferNo end as [Purchase From],  
SQBD.BatchSellQty as SoldQty,SQID.SellPrice,  
SDID.InvoiceNo as [Sales Invoice No],INV.PRInvoiceNo as [PO Invoice No],INV.PRInvoiceDate as [PO Invoice Date],   
SQID.ItemDesc as [Item Description],SQID.NetPrice,SDHM.DeliveryHeaderMasterName as   DeliveryHeaderName,    
SQID.ItemCode as [Item Code],           
SQBD.BatchNo,SQBD.ExpiryDate,SQID.Amount,   
SQID.Dept_ID as Dept_ID,              
Dept_Name as [Department],SQID.Catg_ID as Catg_ID,                                    
Category_Name as [Category],SQID.Brand_ID as Brand_ID,               
BrandName as BrandName, SQID.Manf_Id as Manf_Id,                             
Manf.ManfName as [Manufacturer],              
STM.TaxName, SQID.Tax_ID as Tax_ID,              
INV.VendorID as VendorID,              
SQBD.ItemID,SQM.Isdeleted,  
SDHM.DeliveryHeaderMasterID,Cust.CustomerMasterID        
 from  SD_QuotationMaster SQM                  
inner join  SD_InvoiceDetails SDID on SQM.QuoteID = SDID.QuoteID                
inner join  SD_QuoteItemDetails SQID on SDID.QuoteID = SQID.QuoteID               
inner join  SD_QuoteBatchDetails SQBD on SDID.QuoteID = SQBD.QuoteID and SQID.ItemID=SQBD.ItemID              
inner join  INV_ProductInvoice INV on SQBD.InvoiceID=INV.ProductInvoiceID              
inner jOIN  INV_VendorMaster IVM ON INV.VendorID = IVM.VendorID       
inner jOIN  Sys_TaxMaster STM ON SQID.Tax_ID = STM.Tax_ID                 
inner join Cust_CustomerMaster Cust on SQM.CustomerMasterID = Cust.CustomerMasterID    
left jOIN  INV_DeptartmentMaster Dept ON SQID.Dept_ID = Dept.Dept_ID                                       
left jOIN  INV_BrandMaster BRD ON SQID.Brand_ID = BRD.Brand_ID                                       
left jOIN  INV_ManufacturerMaster  Manf ON SQID.Manf_Id = Manf.Manf_Id                
left join INV_CategoryMaster CAT ON SQID.Catg_ID = CAT.Catg_ID                                                              
left join SLRB_DeliveryCustomerMaster SDCM on SQM.CustomerMasterID=SDCM.CustomerMasterID and SQM.DeliveryHeaderMasterID=SDCM.DeliveryHeaderMasterID                                       
left join SLRB_DeliveryHeaderMaster SDHM on SDCM.DeliveryHeaderMasterID=SDHM.DeliveryHeaderMasterID                               
where (SQM.IsDeleted=0)  and SQBD.BatchSellQty > 0          

and SDID.InvoiceDate between @fromdate and @todate                
order by ItemDesc                     

End 

Only the below tables contain more data while other tables have records less than 20

InvoiceDetails, QuoteMaster, QuoteItemDetails, QuoteBatchDetails ProductInvoice

Below is the link for execution plan

http://jmp.sh/CSZc2x2

Thanks.

Answer 1

Let's start with an obvious error:

(isnull(SQBD.BatchSellQty,0) > 0)

That one is not indexable, so it should not happen. Seriously, BatchSellQty should not be unknown (nullable) in most cases, or you better handle null properly. That field should be indexed and I am not sure I would like that with an isNull - there are likely tons of batches. Also note that a filtered index (condition >0) may work here.

Second, check that you have all proper indices and the execution plan makes sense.

Thids, you have to test with a ton of data. Index statistics may make a difference. Check where the time is spent - it may be tempdb in which case you really need a good tempdb IO speed.... and it is not realted to the input side.

Answer 2

You can try to use query hints to help SQL Server optimizer build a optimal query execution plan. For example, you can force the order of tables will be joined, using FORCE ORDER statement. If you order your tables in order that joins with minimum result size at each step, query will execute faster (may be, needs to try). Example:

We need to A join B join C
If A join B = 2000 records x 1000 records = ~400 records (we suspect this result)
And A join C = 2000 records x 10 records = ~3 records (and this)
And B join C = 1000 records x 10 records = 10 000 records (and this)

In this case optimal order will be

A join C join B = ~3 records x 1000 records = ~3000 records