Blocking issue---help

Question

DELETE FROM #tmpbatch WHERE batchid NOT IN (select distinct #tmpbatch.batchid  from #tmpbatch LEFT JOIN tinvoiceitem ii on ii.batchid = #tmpbatch.batchid
LEFT JOIN tpaymentitem pi on pi.batchid = #tmpbatch.batchid LEFT JOIN tworkorderevent woe on woe.batchid = #tmpbatch.batchid where (ii.servicecenterid IN (select branchid from #tmpuserbranches)) OR (pi.servicecenterid IN (select branchid from #tmpuserbranches))
OR (woe.servicecenterid IN (select branchid from #tmpuserbranches))
               This SQL is in-line SQL in the vb module \App_code\TSPDBSQL\accounting.vb in a public method
named pbatchlistbydate.  This is called from a public method named Get_Batches_By_Date located in the vb module \App_Code\TspAccounting\batch.vb which in turn is called from Office\showbatches.aspx.vb.
               The problem with this block of SQL is the “NOT IN” statement which is selecting from a temp
table that joins back to invoiceitems and paymentitems.  Those joins are causing blocking on the invoice and payment item tables which are used by a lot of SQL in the system.  This SQL needs to be carefully reviewed and optimized so that it does
not introduce unnecesssary scanning of the invoiceitem and paymentitem tables which ultimately blocks other processes.

Answer 1

As we do not know the database structure include indexes, hope this code might be helpful:
CREATE TABLE #NotForDel ( Id INT ) ;
INSERT #NotForDel
( Id )
SELECT tmp.batchid
FROM #tmpbatch AS tmp
LEFT JOIN tinvoiceitem ii ( NOLOCK ) ON ii.batchid = tmp.batchid
LEFT JOIN tpaymentitem pi ( NOLOCK ) ON pi.batchid = tmp.batchid
LEFT JOIN tworkorderevent woe ( NOLOCK ) ON woe.batchid = tmp.batchid
WHERE ( ii.servicecenterid IN ( SELECT branchid
FROM #tmpuserbranches ) )
OR ( pi.servicecenterid IN ( SELECT branchid
FROM #tmpuserbranches ) )
OR ( woe.servicecenterid IN (SELECT branchid
FROM #tmpuserbranches ) ) ;
DELETE t
FROM #tmpbatch AS t
WHERE NOT EXISTS
( SELECT *
FROM #NotForDel AS n
WHERE Id = t.batchid ) ;
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