JOIN
MySQL :: MySQL 8.0 Reference Manual :: 8.2.1.7 Nested-Loop Join Algorithms
MySQL :: MySQL 8.0 Reference Manual :: 8.2.1.4 Hash Join Optimization
NULL
MySQL :: MySQL 8.0 Reference Manual :: 3.3.4.6 Working with NULL Values
MySQL :: MySQL 8.0 Reference Manual :: B.3.4.3 Problems with NULL Values
Does MySQL ignore null values on unique constraints? - Stack Overflow
Index
What are the differences between B trees and B+ trees? - Stack Overflow
MySQL :: MySQL 8.0 Reference Manual :: 15.6.2.1 Clustered and Secondary Indexes
MySQL :: MySQL 8.0 Reference Manual :: 8.3.5 Column Indexes
Cache
MySQL :: MySQL 5.7 Reference Manual :: 8.10.3 The MySQL Query Cache
Transaction
MySQL :: MySQL 8.0 Reference Manual :: 15.7.1 InnoDB Locking
MySQL :: MySQL 8.0 Reference Manual :: 15.7.2.1 Transaction Isolation Levels
MySQL :: MySQL 8.0 Reference Manual :: 15.7.2.3 Consistent Nonlocking Reads
MySQL :: MySQL 8.0 Reference Manual :: 15.7.5.2 Deadlock Detection
MySQL :: MySQL 8.0 Reference Manual :: 15.7.4 Phantom Rows
SQL Statements
MySQL :: MySQL 8.0 Reference Manual :: 13.1.37 TRUNCATE TABLE Statement
Glossary
MySQL :: MySQL 8.0 Reference Manual :: MySQL Glossary - undo log
Design
Storing JSON in database vs. having a new column for each key - Stack Overflow