Indexes • Invisible Indexes • Grouping Optimizer • Cost-based Optimizer • Optimizer Tracing • JSON Explain • Optimizer Hints • Optimizer Histograms MySQL Document Store • Relational Text, etc.) • Server-side Thread Pool • Connection Thread Caching • Diagnostics, and SQL Tracing OLTP and Transactions • ACID Transactions • Commit, Rollback • Foreign Keys • Referential