>>Could you please elaborate more? In orher words, say, you have all indexes (except for deleted) and amount of records to retrieve is small. Does it help to have index in place or not?
>
>It helps to have MOST indices used in the condition. However, if you have a field that takes only a few values - like a logical field "ActiveClient", or an "AgeRange" field that stores only the tens (to discriminate 0-9, 10-19, etc.), then, with an index on that field, too many index keys will have to be retrieved, from the index, for the "optimization" process. That is exactly the problem with an index on deleted() - almost all index keys are retrieved from the index, and only then does the "optimization" process start.
>
>Perhaps you can post your query command, and especially the WHERE clause?

Here it is. I've guessed it's the most time consuming piece, but I need to verify it by some tests:

	lparameters tnNumAccounts, tcUserID, tcQueuePk, ;
		tyLowB, tyHighB, tcAdditionalFilter

* Get the unassigned accounts
	local lcSQL, ldStartDate, lcFutureDate, lcAdditionalJoins

	ldStartDate = this.dStartDate
	lcFutureDate = TimeToStr(datetime(3000,1,1))
	lcAdditionalJoins = ""

	if not empty(m.tcAdditionalFilter) and 'ccarriers_fk' $ lower(m.tcAdditionalFilter)
		text to lcAdditionalJoins noshow pretext 7
		 INNER JOIN Trans_Insurances on ;
		 Trans.cTrans_pk = Trans_Insurances.cTrans_fk
		 INNER JOIN Insurances on ;
		 Trans_Insurances.cInsurances_fk = Insurances.cInsurances_pk ;
		 INNER JOIN Carrier_Branches on ;
		 Insurances.cCarrier_Branches_fk = Carrier_Branches.cCarrier_Branches_pk
		ENDTEXT
	endif

	if used('curAccountsToAssign')
		tcAdditionalFilter = strtran(m.tcAdditionalFilter,"Trans.","",-1,-1,1)
		lcAdditionalJoins = strtran(m.lcAdditionalJoins,"Trans.","",-1,-1,1)
		text TO lcSQL TEXTMERGE NOSHOW PRETEXT 7
				select top <<m.tnNumAccounts>> *, 0 as iAssigned ;
					from curAccountsToAssign ;
					<<m.lcAdditionalJoins>> ;
					where between(yCurrent_Balance_Amount, <<m.tyLowB>>, <<m.tyHighB>>) ;
					AND cQueue_Names_fk = '<<m.tcQueuePk>>'
		ENDTEXT
	else
		text TO lcSQL TEXTMERGE NOSHOW PRETEXT 7
				select top <<m.tnNumAccounts>> trans.cTrans_pk, ;
					NVL(Employee_Queue_Schedules.tScheduled_Time, <<m.lcFutureDate>>) as tScheduled_Time, ;
					Trans_Employees_Queues.cTrans_Employees_Queues_Pk, 0 as iAssigned, ;
					space(16) as cCommission_Owner_UsGrLink_fk, ;
					space(16) as cQueue_names_fk ;
					from trans INNER join Trans_Employees_Queues ;
					on trans.cTrans_pk = Trans_Employees_Queues.cTrans_fk ;
					LEFT JOIN Employee_Queue_Schedules ON ;
					Trans_Employees_Queues.cTrans_Employees_Queues_pk = ;
					Employee_Queue_Schedules.cTrans_Employees_Queues_fk ;
					and Employee_Queue_Schedules.iActive_Flag = 1 ;
					<<m.lcAdditionalJoins>> ;
					where Trans_Employees_Queues.cCommission_Owner_UsGrLink_fk IS NULL ;
					and Trans_Employees_Queues.cQueue_names_fk = '<<m.tcQueuePk>>' ;
					and trans.cDepartment_Code like '<<this.cDepartment_Code>>' ;
					and trans.cResolution_Codes_fk is NULL ;
					and	Trans.iAccount_locked_flag = 0 ;
					and between(trans.yCurrent_Balance_Amount, <<m.tyLowB>>, <<m.tyHighB>>) ;
					and Trans_Employees_Queues.iActive_Flag = 1
		ENDTEXT
	endif

	lcSQL = m.lcSQL + iif(not empty(m.tcAdditionalFilter), ;
		" AND " + m.tcAdditionalFilter,"") + ;
		" AND tExpire_date < " + DateToStr(m.ldStartDate) + ;
		" order by tScheduled_Time, tDate_Received"

Notice the m.tcQueuePk parameter. We have ~100K records with ~100-200 of UNASSIGNED BILLER queue.