If you delete a version does it delete all the issues?

[Ben GP]

This question is in reference to Atlassian Documentation: Managing versions

I am having issues setting up and using JIRA for versions. I imported from Pivotal which just made a mess so I deleted all the version but it seemed to delete all my completed issues in the past week. 

[Nic Brough -Adaptavist- · Accepted solution]

No, it just removes the version.  Of course, that means the version is stripped off the issues it was on, but it makes no change to the rest of the issue.

My guess is that your "completed issues in the past week" filter was using the version to identify them