PostgreSQL - help, no logro hacer que funcione, sigo teniendo problemas con

SELECT f.flagspace

    FROM (SELECT

        CASE

        WHEN a.max_space_table_diff_qty > COALESCE(b.currentperm_hist, 0) THEN

        'S'

        ELSE 'N'

        END AS flagspace

    FROM

        (SELECT publish_information_id,

         service_information_id,

         CAST (COALESCE(max_space_table_diff_qty,

         0) AS INTEGER) AS max_space_table_diff_qty

        FROM ${CTL_DB}.settings_precedent_fx

        WHERE publish_information_id = '1003'

                AND service_information_id = '1032') AS a LEFT OUTER

        JOIN

            (SELECT publish_information_id,

         service_information_id,

         CAST (COALESCE(SUM(currentperm) / 1024 / 1024,

         0) AS INTEGER) AS currentperm_hist

            FROM dbc.tablesize AS dbc

            INNER JOIN ${CTL_DB}.settings_precedent_fx AS spf

                ON (dbc.tablename = spf.service_info_table_name)

            WHERE CurrentPerm_HIST.databasename = '$BBDD_HIST'

                    AND publish_information_id = '1003'

                    AND service_information_id = '1032'

            GROUP BY  1, 2) AS b

                ON (a.publish_information_id = b.publish_information_id

                    AND a.service_information_id = b.service_information_id)) AS f

        WHERE f.flagspace = 'S';

CREATE SCHEMA IF NOT EXISTS schema_name;