Adding Data-Engineering since we will work with them on the technical details.

Hi! I want to clarify that the following are code functions and not database fields:

• User::isRegistered() will return true for all registered accounts, including temporary accounts.
• User::isAnon() will return false for such temporary accounts.
• User::isTemp() will return true exclusively for temporary accounts.
• User::isNamed() will return true exclusively for registered accounts that are not temporary accounts.

Under the currently proposed plan, temp accounts will have user IDs just like a registered account and the best way to identify temp accounts will be to run a regex on the username column and look for usernames beginning with an asterisk (*).
There are ongoing conversations between Data Engineering and DBAs about the possibility of adding an explicit flag to identify temp accounts on the user table.

updates from meeting with @kzimmerman , @Iflorez and @jwang

• Where do we track or report anonymous editors? what could be impacted?
  • Form 990
  • Community Insights annual reporting?
  • Wiki Comparison
  • Equity Dashboard
• What will break?
  • any code that relies on user_is_anonymous being purely anonymous users
  • any of the above reports of queries we have that uses event_user_id = 0 to calculate anonymous users

• What should we be prepared for?
  • We do get questions on anonymous editors some times and it would be helpful if we have that on hand
  • Monitor as IP masking rolls out and differentiate between these 2 groups
  • given past experience, Build in buffers to deal with consequences and broken jobs/queries!

@Milimetric , can we pls get a list of all the tables where the proposed changes will be applied?

Next:

• discuss in Product-Analytics sharing meeting
• alternate proposal: in tables like mediawiki_history, can we have a separate column called unregistered_user_id to store the temporary user ids? this will avoid breaking queries that use event_user_id=0 to identify anonymous users since temporary and anonymous users both will have this field = 0. what would be its implications ?

After my discussion with Product-Analytics as well as Research and Decision Science, @Milimetric , @nshahquinn-wmf and I started discussing how the different types of users - registered, temporary, anonymous (ip) are defined in the upstream mediawiki tables vs. downstream data tables with the introduction of the new "temp" user.
This is being discussed with a larger audience in this discussion https://www.mediawiki.org/wiki/Talk:User_account_types#What_does_%22anonymous%22_mean and in T337103. Once we resolve this we can clarify definitions around anonymous and temporary editors.