Redmine

Fred B wrote:

Please do not delete it or mark it as duplicate!

This issue is not counted in Redmine.org tickets vote count list(2019/12/22).
Is it OK?

When you delete data from Redmine, it will actually be deleted and not just marked as "hidden" in the database. For most data, especially for issues, this is required since existing issues (with e.g. relations or parent-child connections) can affect other issues.

Assuming you would "delete" issues by hiding them, these these hidden issues would then need to be adapted with changes from parent issues or issue relations (and their rules enforced) so that they can later be "undeleted" and still show a consistent view. This would then result in problems since these hidden issues could enforce unexpected rules. On the other hand, being able to actually delete data is a nice feature of Redmine since it allows to follow data protection rules which might enforce the full deletion of data.

Now, you can deny normal users the ability to delete issues in the first place by removing the "Delete issues" permission from their roles. That way, they would only be able to close issues (or mark them e.g. with an "Invalid" status according to the defined workflow. This along would be quite effective for about all users. The only exception would be Administrators who have all permissions and can thus delete data. If this is a concern, you should not set the Admin flags on users and use these accounts only sparingly. In the end, admins can probably delete the raw data from the database anyways.