JOIN Types Index

ALL

Section 7.3.1.8, “Nested-Loop Join Algorithms”

const

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.11, “ORDER BY Optimization”
Section 12.2.8, “SELECT Syntax”
Section 16.3.4.3, “MySQL Cluster System Variables”
Section 7.3.1.3.1, “The Range Access Method for Single-Part Indexes”

eq_ref

Section 7.2.2, “EXPLAIN Output Format”
Section 13.8.1, “MERGE Table Advantages and Disadvantages”
Section 16.3.4.3, “MySQL Cluster System Variables”
Section 7.3.1.14, “Optimizing IN/=ANY Subqueries”

fulltext

Section 7.2.2, “EXPLAIN Output Format”

index

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.8, “Nested-Loop Join Algorithms”

index_merge

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.4, “Index Merge Optimization”

index_subquery

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.14, “Optimizing IN/=ANY Subqueries”
Section 12.2.9.10, “Optimizing Subqueries”

range

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.4, “Index Merge Optimization”
Section 7.3.1.12.1, “Loose Index Scan”
Section 7.3.1.8, “Nested-Loop Join Algorithms”
Section 7.3.1.3, “Range Optimization”
Section 7.3.1.3.1, “The Range Access Method for Single-Part Indexes”

ref

Section 7.2.2, “EXPLAIN Output Format”
Section 13.8.1, “MERGE Table Advantages and Disadvantages”
Section 7.5.4, “MyISAM Index Statistics Collection”
Section 16.3.4.3, “MySQL Cluster System Variables”
Section 7.3.1.14, “Optimizing IN/=ANY Subqueries”

ref_or_null

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.6, “IS NULL Optimization”
Section 7.3.1.14, “Optimizing IN/=ANY Subqueries”

system

Section 7.2.2, “EXPLAIN Output Format”
Section 12.2.8, “SELECT Syntax”
Section 16.5.6.1, “MySQL Cluster: Messages in the Cluster Log”
Section 7.3.1.3.1, “The Range Access Method for Single-Part Indexes”

unique_subquery

Section 7.2.2, “EXPLAIN Output Format”
Section 7.3.1.14, “Optimizing IN/=ANY Subqueries”
Section 12.2.9.10, “Optimizing Subqueries”