What is considered a large data set?

[Trace Magill]

This question is in reference to Atlassian Documentation: Migrating to Another Database

Do you have a pseudo limit on what is considered a large data set that makes the .xml backup and restore a non starter?

I have 1 GB in a DB and 17 GB on disk... about 11k pages.  and about 10 versions of each.

[Steven F Behnke]

I can help here, we've done this a ton. 17gb attachments is right out, do not back up with XML with attachments. 

11k pages, 1gb is a medium sized instance from my point of view, however you may run into Out of Memory errors pointing to heap space even at that size. So even if you choose XML without Attachments, you may need to increase the amount of heap in your JVM to do so.

Restoring attachments and the database from backup may be a more desirable workflow to prevent these sort of configuration changes and issues.