privacy – What technical challenges prevent non-centralized messaging apps from servicing billions of users?

The most popular messaging apps to date (e.g. telegram), even those that are “privacy by design” (e.g. signal, threema), are centralized.

What technical challenges prevent peer-to-peer (e.g. jami) or decentralized (e.g. blockchain) messaging apps from servicing billions of users?

How to implement popup for new users?

I found a nice popup implementation https://magento.stackexchange.com/a/222160/85778, but how do I define new users?

For example. If 48 hours have not passed since the creation of the user, then it is considered new.

postgresql – Default Users for Postgres

The default User is created during installation of the server instance. But you can query for a list of all current Users using this query:

SELECT usename AS role_name,
  CASE 
     WHEN usesuper AND usecreatedb THEN 
       CAST('superuser, create database' AS pg_catalog.text)
     WHEN usesuper THEN 
        CAST('superuser' AS pg_catalog.text)
     WHEN usecreatedb THEN 
        CAST('create database' AS pg_catalog.text)
     ELSE 
        CAST('' AS pg_catalog.text)
  END role_attributes
FROM pg_catalog.pg_user
ORDER BY role_name desc;

For more information please see this article.

You can change the Users and their passwords using ALTER USER, as discussed here. You can also disable the login for the default User as stated here.

subdomain – How can I assign a custom url on my domain to users who join my site?

I have a site that offers a subscription service.
I want to assign a custom url to my customers as I have seen some services do.

For example, if my domain name is www.example.com and my customer url name is ‘customer1’, how can I make a custom url as follows: www.customer1.example.com?

I have seen a site that des this and would like to replicate the same.

Synced files on OneDrive if a user’s permission got removed from SharePoint

What will happen inside the synced OneDrive files if the user’s permission got removed from SharePoint.

  1. let say user A have contribute permission on siteA, and he synced files from the SharePoint site into his overdrive desktop app.

  2. and he chose to always show the files on his desktop.

  3. then UserA’s permission got removed from the SharePoint site >> so what will happen to the files inside the OneDrive app? will the user be able to view those files? or those files will also get removed from his OneDrive app, since he no longer can view them inside SharePoint?

Synced files on OneDrive if a user’s permision got removed from SharePoint

What will happen inside the synced one-drive files if the user’s permission got removed from SharePoint.

  1. let say user A have contribute permission on siteA, and he synced files from the SharePoint site into his overdrive desktop app.

  2. and he chose to always show the files on his desktop.

  3. then UserA’s permission got removed from the SharePoint site >> so what will happen to the files inside the overdrive app? will the user be able to view those files? or those files will also get removed from his overdrive app, since he no longer can view them inside SharePoint?

Want to add more options on User database schema to premade users

So I have this User MongoDB Schema, and I want to add other options to it. but if I do then the current users have to create a NEW Account to see the new changes. is there a way to update all the current users’ schema to show the new one?

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Best representation when we need users to pick only Sundays of every week as date

I have a date input field and it should only display Every Sunday for next one year for user selection.

How can we effectively design this?