SELECT BQT1.SmallA.IntKey AS SmallA_IntKey, BQT2.MediumB.IntKey AS MediumB_IntKey, BQT2.LargeB.IntKey AS LargeB_IntKey
FROM
    (
        BQT1.SmallA LEFT OUTER JOIN BQT2.MediumB
             ON BQT1.SmallA.IntKey = BQT2.MediumB.IntKey
    )
    RIGHT OUTER JOIN BQT2.LargeB
         ON BQT2.MediumB.IntKey = BQT2.LargeB.IntKey
WHERE BQT2.LargeB.IntKey < 1500

SELECT g_1."intkey" AS c_0, g_2."intkey" AS c_1, g_0."intkey" AS c_2
FROM
    "bqt-server"."dvqe"."LargeB" AS g_0 
    LEFT OUTER JOIN
    "bqt-server"."dvqe"."SmallA" AS g_1
    INNER JOIN "bqt-server"."dvqe"."MediumB" AS g_2
    ON g_1."intkey" = g_2."intkey"
    ON g_2."intkey" = g_0."intkey"
AND g_2."intkey" < 1500
WHERE g_0."intkey" < 1500