What does an administrator need to know about SQL and DBMS?

Question

SQL

Good afternoon. Newbie question.
The situation is this: I am a sysadmin and I often come across the concepts of SQL, PostgreeSQL, MySQL, etc.
At the same time, I don’t know anything but the name, but I want to know.
And to know at the level so that I can administer the database, in which case, perform a backup, restore, etc.
In general, I want to understand what it is and what they eat with.
I need a list of sources from where and in what order I can get this knowledge, thanks.

Answer 1

A good admin is everything.
Medium: backups, restores, transaction management and basic sequel commands. in addition to understand what a table is, what it consists of, triggers, projections, stored procedures, and so on and so forth.

Answer 2

Rzheutskaya S.Yu. - Database. SQL language - 2010
Igor Simdyanov - Mysql in the original