SELECT last, language
FROM agent NATURAL JOIN languagerel NATURAL JOIN language 
WHERE language <> 'Russian' and salary > 62000
=====================================================
Hash Join  (cost=64.24..123.75 rows=974 width=31)

  Hash Cond: (languagerel.lang_id = language.lang_id)

  ->  Hash Join  (cost=19.32..65.44 rows=974 width=11)

        Hash Cond: (languagerel.agent_id = agent.agent_id)

        ->  Seq Scan on languagerel  (cost=0.00..28.91 rows=1991 width=8)

        ->  Hash  (cost=15.28..15.28 rows=324 width=11)

              ->  Seq Scan on agent  (cost=0.00..15.28 rows=324 width=11)

                    Filter: (salary > 62000)

  ->  Hash  (cost=27.50..27.50 rows=1393 width=28)

        ->  Seq Scan on language  (cost=0.00..27.50 rows=1393 width=28)

              Filter: ((language)::text <> 'Russian'::text)