Hi!
I maybe I din't understand ALL that you want. So few questions, what's the PLAN of your actual query?
What the diference yours from this one below?

SELECT * FROM PHYSICAL_COPY a
INNER JOIN COPY_CLASSIFICATION ON a."COPY_ID" = COPY_CLASSIFICATION."COPY_ID"
INNER JOIN COPY ON COPY_CLASSIFICATION.COPY_ID = COPY."ID";
WHERE (a."REPOSITORY_TYPE" = 'blah')

Can you provide what time is spend in each time for the querys?(prepare, fetch, execute...)
also, what version of FB?

regards,