What book to read to improve knowledge of SQL?

Question

SQL

What book to read to improve knowledge of SQL? Complex requests. query optimization, work with highload projects. Now we often have to optimize projects that have more than 100 million records in the databases, but what is the best way to do it while difficulties arise, so tell me which books to read?

Answer 1

read the documentation of a specific DBMS.
optimizers (this is such a utility that tries to build an optimal query plan) are different everywhere, although the general optimization rule is the same and unbreakable: fewer operations with physical media.