# NOTE
# The records will be sorted by the post date, in ASCending order (newest to
# oldest), which means posts created later are assumed as duplicates. Example
# cases, where post-1 and post-2 have the *same slug* and created by the *same author*:
#   1) post-1 created on Nov 1st; post-2 created on Nov 2nd; so post-2 is a duplicate.
#   2) Same as #1 above, but post-2 was updated on Nov 3rd; so post-1 is a duplicate.
# because the column post_date is changed when the post is created/updated.

# Outer query - Select duplicate records.
SELECT p.ID, p.post_author, p.post_name, p.post_type, p.post_status
FROM wp_posts p
    INNER JOIN wp_posts p2 ON p2.post_author = p.post_author
WHERE p.ID NOT IN (
    # Sub-query - Select original records.
    SELECT ID
    FROM wp_posts
    GROUP BY post_author, post_name
    HAVING ( COUNT(post_author) > 1 )
        AND ( COUNT(post_name) > 1 )
    # This should match the outer's ORDER BY
    ORDER BY post_date ASC
)
    AND p.ID != p2.ID
    AND p.post_name = p2.post_name
# This should match the sub-query's ORDER BY
ORDER BY p.post_date ASC
LIMIT 15