Delete history on patient archive and clean them out of db

[colinxfleming]

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• What are we trying to do?

While doing something unrelated in db I noticed that we have a bunch of spare ~Audit Trail~ PaperTrailVersion objects hanging out, including from patients that have been archived or deleted. We should remove these, since we don't need them after patient archive.

• What feature or behavior is this required for?

Keeping db memory usage down (AuditTrails take up almost half of our db usage). This will let us not

• How could we solve this issue? (Not knowing is okay!)

Here's what I'd suggest:

• On ArchivedPatient#convert_patient, destroy all audit trail objs associated with a given patient as part of that process

• In the nightly_cleanup task, establish a safety net by deleting any audit trail obj older than a year.

• Anything else?

nope!

[colinxfleming]

@elimbaum would love for you to work on this next when you get headroom

[elimbaum]

some questions:

• destroy or delete? delete was giving me errors, assuming this is because it doesn't also delete related objects, whereas destroy does. just want to confirm this is ok.
• should we be deleting audit objects created over a year ago, or last updated a year ago?

[elimbaum]

Not totally sure how to best test this. In paper_trail_version_test.rb I try to manually set a version to be really old, but the change seems to not be picked up, so nothing is deleted...

[colinxfleming]

Run with destroy. The difference iirc is that delete doesn't fire callbacks but destroy does; PaperTrailVersion shouldn't have any dependent objects or trigger any callbacks. You also might be able to use destroy_all to nuke the whole set.

Also, created a year ago please! But tbh they should be the same for everything, I generally think of these as immutable.

For testing, you might want to try out timecop. I forget the exact syntax but probably something like:

with_versioning do 
  Timecop.freeze('2001-01-01') do
    Patient.create ...
  end
end
PaperTrailVersion.first # should have a created at / mod at on 2001-01-01 at midnight, I think

[elimbaum]

timecop! cool! that would also explain why i wasn't able to manually modify PaperTrail at attributes. I'll give this a go!