Thoughts on querying ID card information

Loading editor...
Problem introduction:

On Sunday and in the morning, I went out for a stroll with a friend to breathe fresh air. Several policemen are checking their ID cards when taking the subway. It is said that the closing ceremony of the Universiade is in the window of the world, so it has been relatively strict recently. You only need to put your ID card on a machine to record your personal identity information. If you forget to bring your ID card or report it to your ID card number, you can check it out. Okay, I thought about how their system is implemented.

Question conjecture:

1. Database Design

How is this database designed for billions of citizens across the country with such a huge data volume?

2. How to ensure data security

Such a large amount of citizenship information is leaked, and the consequences are unimaginable. (Permission management)

3. Speed assurance

How can we ensure the speed of such a large database? Cache (level 1, level 2, level 3 cache )...