Sharding and backup/restore?

Question

MySQL

If you use horizontal sharding and the database is "spread" over several servers (for example, the shards of one large table will be spread over 2 or more physical servers), then how to back up the database and, most importantly, how to restore it (for example, a table is deleted )? In which DBMS (MySQL, Postgres) is this even possible? Please share if you have experience.

Answer 1

for example, the shards of one large table will be spread over 2 or more physical servers

What is this for?
They don't do that. Horizontally done to increase the speed of return.
Of course, you can spread the data to different servers, but this is done at the level of the business logic architecture, and not at the level of one table.

Answer 2

Even without sharding, the correct backup of a large database is not a trivial task.
Sharding is even more difficult. See for example https://dzone.com/articles/mysql-sharding-devops-c... and others on the topic "sharding backup".
If you do not have a DBA, I advise you to use managed services - AWS RDS, etc.