There are times that Confluence ancestor CONFANCESTORS table gets out of sync which could cause some bizarre issues.

Currently, the only way to identify this is to wait until a user hit into the above issues or any unknown upcoming issue. This is very hard to catch. And currently, one would need to rebuild it manually.

It'd be nice if the health state of CONFANCESTORS table can be identified from an accessible page in admin console or perhaps in the System Information (would be a huge win for Support).

It'd be even nicer if Confluence would automatically rebuild the ancestor table once it's detected to be out of sync or corrupted.

Workaround

Quoting from this KB - Unable to Move Pages with Attachments. This can be checked manually by running this SQL query:

SELECT A.ANCESTORID, A.DESCENDENTID, COUNT(A.DESCENDENTID)
FROM CONFANCESTORS A, CONTENT B
WHERE B.CONTENTID = A.DESCENDENTID
GROUP BY A.ANCESTORID, A.DESCENDENTID
ORDER BY 3 DESC

All returned rows should have value '1' for the column 'count'. If there is a value other than '1' (e.g. '2', '3', etc.), the CONFANCESTORS table is broken.