MySQL index optimization solution

• Chapter1 Index introduction
• 1-1 what is index
• 1-2 Index data structure
• 1-3 Advantages and Disadvantages of Indexing
• 1-4 Index classification
• Chapter2 MySQL index-Explain
• 2-1 Index test
• 2-2 explain
• 2-3 Explain ID introduction
• 2-4 Explain's select_type introduction
• 2-5 Explain type introduction -1
• 2-6 Explain type introduction -2
• 2-7 Explain type introduction -3
• 2-8 Explain's possible keys and key introduction
• 2-9 Explain's ref introduction
• 2-10 Introduction to Explain
• 2-11 Explainvalueextra introduction
• Chapter3 MySQL index - index failure
• 3-1 Index invalidation -1
• 3-2 Index failure -2
• 3-3 Index failure -3
• Chapter4 MySQL Index-Optimization
• 4-1 Sorting optimization
• 4-2 Optimization case
• 4-3 Joint table query optimization
• 4-4 Group query optimization
• 4-5 Slow query log