Как улучшить перманентность запроса select ?

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Я снова застрял с производительностью запросов к базе данных..

Один запрос Select-занимает много времени для выполнения - 7 минут для 30 записей.

Что я уже пробовал:

select distinct incoming.IC_NO,
(case when ISNUMERIC(incoming.IC_RECEIVERS_SR_ID) <> 1 then incoming.IC_RECEIVERS_SR_ID when ISNUMERIC(incoming.IC_RECEIVERS_SR_ID) = 1
then (select sr.SR_NAME from SENDERRECEIVER sr where sr.SR_ID = cast( incoming.IC_RECEIVERS_SR_ID as numeric) )end) as 'IC_RECEIVERS_SR_ID',
(select courier.CSP_NAME from COURIERSERVICEPROVIDER courier where courier.CSP_ID = incoming.IC_CSP_ID) as 'Courier Service Name',
equip.EQ_DESC as 'Site',
(select REPLACE(t.EQ_DESC,'–','') from EQUIPMENT t where t.EQ_L1 = equip.eq_code and t.EQ_LEVEL = 2 and incoming.IC_SUBHUBLOC = t.EQ_CODE) as 'Subhurb',
incoming.IC_WEIGHT, incoming.IC_RATE , incoming.IC_CONSIGNMENTRECDATETIME,
incoming.IC_ReceiverCity as 'Receiver City',
incoming.IC_RECEIVERPINCODE as 'Receiver Pincode',
incoming.IC_AIRWAYBILLNO as 'Airway Bill No',
incoming.IC_AMOUNT as 'Amount', incoming.IC_CREATEDBY as 'Created By',
incoming.IC_COURIERTYPE as 'Courier Type'
from INCOMINGCONSIGNMENT incoming , equipment equip,
equipment subhurb where 1=1 and IC_CONSIGNMENTRECDATETIME between '03 Jul 2017' and '03 Jul 2017' 

Пожалуйста, помогите мне...

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