The optimization process and recommendations:

1. Avoid LIKE Searches With Leading Wildcard (query line: 24): The database will not use an index when using like searches with a leading wildcard (e.g. '%WAFERCT%'). Although it's not always a satisfactory solution, please consider using prefix-match LIKE patterns (e.g. 'TERM%').
2. Avoid Subqueries (query line: 11): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
3. 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.

Optimal indexes for this query:

CREATE INDEX machine_signal_idx_signal_id_machine_id ON MACHINE_SIGNAL (SIGNAL_ID,MACHINE_ID);
CREATE INDEX tsd_sub_idx_machine_id ON TSD_SUB (MACHINE_SIGNAL_ID);

The optimized query:

SELECT
        DISTINCT q1.MACHINE_ID,
        q1.SIGNAL_ID,
        ROUND(86400000 * (REGR_SLOPE(ts.VALUE,
        ts.EPOCH) OVER (PARTITION 
    BY
        ts.MACHINE_SIGNAL_ID ))) AS RATE,
        q1.LAST_VALUE 
    FROM
        TSD_SUB ts,
        (SELECT
            ms.MACHINE_SIGNAL_ID,
            ms.LAST_TIMESTAMP 
        FROM
            MACHINE_SIGNAL ms 
        WHERE
            (
                ms.MACHINE_ID LIKE 'CV%'
            ) 
            AND (
                ms.SIGNAL_ID = ANY(
                    'WFRCOUNT', 'WFRCNTR'
                ) 
                OR ms.SIGNAL_ID LIKE '%WAFERCT%'
            )) q1 
    WHERE
        ts.MACHINE_SIGNAL_ID = q1.MACHINE_SIGNAL_ID 
        AND ts.EPOCH > (
            q1.LAST_TIMESTAMP - 604800000
        )