The optimization process and recommendations:

1. Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
2. Remove Redundant Left Joins (modified query below): Redundant LEFT JOINs (e.g. `BAR`) were detected in the query. Removing them will result in a performance improvement. In some cases, JOINs become redundant after an optimization is applied, such as when converting OR conditions to a UNION clause.

Optimal indexes for this query:

CREATE INDEX foo_idx_foo_id ON FOO (FOO_ID);
CREATE INDEX gee_idx_gee_id ON GEE (GEE_ID);

The optimized query:

SELECT
        DISTINCT FOO.FOO_ID AS C0,
        GEE.GEE_CODE AS C1,
        TO_CHAR(FOO.SOME_DATE,
        'DD/MM/YYYY') AS C2,
        TMP_FOO.SORT_ORDER AS SORT_ORDER_ 
    FROM
        TMP_FOO 
    INNER JOIN
        FOO 
            ON TMP_FOO.FOO_ID = FOO.FOO_ID 
    LEFT JOIN
        GEE 
            ON FOO.GEE_ID = GEE.GEE_ID 
    ORDER BY
        SORT_ORDER_