Section 8.2.1.3, “Index Merge Optimization” Section 8.8.2, “EXPLAIN Output Format” Section 8.2.2.3, “Optimizing Subqueries with the EXISTS Strategy” range index_subquery R [index top] Section 8.2.1.12, “Block Nested-Loop and Batched Key Access Joins” Section 8.8.2, “EXPLAIN Output Format” Section 8.2.1.17, “GROUP BY Optimization” Section 8.2.1.6, “Index Condition Pushdown Optimization” Section 8.2.1.3, “Index Merge Optimization” Section 8.2.1.7, “Nested-Loop Join Algorithms” Section 8.9.3, “Optimizer Hints” Section 8.2.1.2, “Range Optimization” Section 8.2.1.12, “Block Nested-Loop and Batched Key Access Joins” Section 8.8.2, “EXPLAIN Output Format” Section 8.8.3, “Extended EXPLAIN Output Format” Section 8.2.1.6, “Index Condition Pushdown Optimization” Section 8.3.8, “InnoDB and MyISAM Index Statistics Collection” Section 16.7.1, “MERGE Table Advantages and Disadvantages” NDB Cluster System Variables Section 8.9.3, “Optimizer Hints” Section 8.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization” Section 8.2.2.3, “Optimizing Subqueries with the EXISTS Strategy” ref ref_or_null system S [index top] Section 8.8.2, “EXPLAIN Output Format” Section 8.2.1.6, “Index Condition Pushdown Optimization” Section 8.2.1.15, “IS NULL Optimization” Section 8.2.2.3, “Optimizing Subqueries with the EXISTS Strategy” Section 8.8.2, “EXPLAIN Output Format” Section 8.8.3, “Extended EXPLAIN Output Format” Section 8.2.1.2, “Range Optimization” Section 13.2.10, “SELECT Statement” U 5738 [index top]