Bleh. Google-Code-in-2019 is a great time to realize that my previous patch does not help either. :P Again, phrasing the goal as a reminder to myself: Identify and follow up on users who assigned their first Phab tasks ever to themselves. And not only identify new folks when/if/once they managed to put something into Gerrit.

My original idea in the patch above was using the task URLs to manually flagging specific (task-based) emails in my local mail client and then recheck on tasks via that flag. But realized that my bugmail filters will filter out some of the bugmail for those tasks claimed by new contributors, so that won't work.
Manually clicking the links and checking all links every week does not scale either. Last week these were 58 links and most of them need no followup.

Current query is meh:

1. claimed is not the actual assignment date but the last any update date on that task.
2. Also lists resolved tasks.
3. Inclusion criterion is "user created their user account in last six weeks and has at least one task assigned to them". Last week that meant that one assignee has 13 tasks listed (11 of them resolved).

What to do:

1. Actual assignment date is only in the transactions table which is too expensive to query. Won't fix that.
2. Add t.closerPHID IS NULL. Reduces the result set for last week from 58 (any status) tasks to 30 (open) tasks.
3. Add a threshold not to list assignees when they have 4 or more assigned tasks in total, by adding a HAVING subquery. So one assignee would be listed max three times (if they assigneed three or more tasks to themselves within six weeks after registering their Phab account). This cuts downlast week's result set from 58 to 18 entries which is something that I might be able to manage.