update mb__model2serv_all set "price" = 
        (
               select "priceAll" FROM mb__price2item 
                    WHERE mb__price2item."itemId" = mb__model2serv_all."linkId" 
                              and mb__price2item."priceRegionId" = mb__model2serv_all."regionId"
         )
       where mb__model2serv_all.price = 'Звоните'

shared_buffers = 4096MB			# min 128kB
					# (change requires restart)
temp_buffers = 256MB			# min 800kB
#max_prepared_transactions = 0		# zero disables the feature
					# (change requires restart)
# Note:  Increasing max_prepared_transactions costs ~600 bytes of shared memory
# per transaction slot, plus lock space (see max_locks_per_transaction).
# It is not advisable to set max_prepared_transactions nonzero unless you
# actively intend to use prepared transactions.
work_mem = 2048MB				# min 64kB
maintenance_work_mem = 2048MB		# min 1MB
#max_stack_depth = 2MB			# min 100kB

explain
update mb__model2serv_all set "price" = mb__price2item."priceAll"
from mb__price2item
where mb__price2item."itemId" = mb__model2serv_all."linkId"
and mb__model2serv_all."price" = 'Звоните'

Update on mb__model2serv_all  (cost=57125.97..576110.72 rows=1768870 width=256)
  ->  Hash Join  (cost=57125.97..576110.72 rows=1768870 width=256)
        Hash Cond: (mb__model2serv_all."linkId" = mb__price2item."itemId")
        ->  Seq Scan on mb__model2serv_all  (cost=0.00..435522.06 rows=365411 width=242)
              Filter: ((price)::text = 'Звоните'::text)
        ->  Hash  (cost=40357.10..40357.10 rows=1341510 width=22)
              ->  Seq Scan on mb__price2item  (cost=0.00..40357.10 rows=1341510 width=22)