No need to touch MySQL directly.

What he wants to do can be done with a simple python script setup as an hourly crontab job.

Here's the code to clear the active event console:

#!/usr/bin/env python
import Globals
from Products.ZenUtils.ZenScriptBase import ZenScriptBase
from transaction import commit

dmd = ZenScriptBase(connect=True).dmd

for e in dmd.ZenEventManager.getEventList([], "", "lastTime ASC, firstTime ASC"):
    dmd.ZenEventManager.manage_deleteEvents(e.evid)

Save that as a .py, and setup a crontab job to execute the script every hour (under the zenoss user account).

Cheers.

1. No event details data will be lost at all, it will be as though you selected all events and did move to history by hand.

2. The function is misleading, I know it says deleteEvents but what it will actually do is simply move the events from the active event console to history.  No events will be removed from the MySQL database at all.

Help yourself

I'm not sure that would work.  I would personally do it this way...

#!/usr/bin/env python
import Globals
from Products.ZenUtils.ZenScriptBase import ZenScriptBase
from transaction import commit

dmd = ZenScriptBase(connect=True).dmd

for e in dmd.ZenEventManager.getEventList([], "", "lastTime ASC, firstTime ASC"):
    evt = dmd.ZenEventManager.getEventDetailFromStatusOrHistory(e.evid)
    if evt.severity < 4:
        dmd.ZenEventManager.manage_deleteEvents(evt.evid)

My pleasure.

That would be pretty complex to do.  You'd have to convert the first time and last time to epoch time and then figure out the amount of time between them to determine the total age of each event (and then perform the action based on that).  I have some projects on the go so I don't currently have time to work out how to do that.

Note: the times are stored as epoch time in MySQL, so there may be some way to directly extract that using Python.