Background

A page has a set of previous versions. Sometimes previous versions could have different parents or different spaces. Parents could be either from current space or from other spaces.
It could happen if the page is moved to another page or space.
As a result, the import process of such spaces could fail with "could not execute statement".

Expected behaviour

Previous versions must not have different parents or spaces.

Workaround

https://confluence.atlassian.com/confkb/importing-a-space-fails-with-could-not-execute-statement-error-in-confluence-server-949242294.html

Additional information

To test if database is affected by bug, this script could be run:

SELECT COUNT(*)
FROM CONTENT
JOIN CONTENT xpage ON CONTENT.PREVVER = xpage.CONTENTID
WHERE CONTENT.SPACEID != xpage.SPACEID;

If it returns non-zero value, database is affected by this bug.