Find missing records that match descriptions

-- find all ids and descriptions from source table that are not in destination table
-- but already have a matching description in the destination table
SELECT DISTINCT s.uid, s.desc
FROM source_db..source_table s
LEFT JOIN dest_db..dest_table d ON d.uid = s.uid
WHERE s.delete_flag = 'N' AND d.uid IS NULL AND s.desc IN
(
    SELECT DISTINCT CONVERT(VARCHAR(MAX), t2.desc) FROM dest_db..dest_table t2
);

-- note: must convert "desc" field datatype to varchar from text.