JOIN Types Index

ALL

Section 7.2.10, “Nested-Loop Join Algorithms”

const

Section 7.2.13, “ORDER BY Optimization”
Section 12.2.8, “SELECT Syntax”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 7.2.5.1, “The Range Access Method for Single-Part Indexes”

eq_ref

Section 7.2.16, “Optimizing IN/=ANY Subqueries”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 13.8, “The MERGE Storage Engine”

fulltext

Section 7.2.1, “Optimizing Queries with EXPLAIN

index

Section 7.2.10, “Nested-Loop Join Algorithms”
Section 7.2.1, “Optimizing Queries with EXPLAIN

index_merge

Section 7.2.6, “Index Merge Optimization”
Section 7.2.1, “Optimizing Queries with EXPLAIN

index_subquery

Section 7.2.16, “Optimizing IN/=ANY Subqueries”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 12.2.9.10, “Optimizing Subqueries”

range

Section 7.2.6, “Index Merge Optimization”
Section 7.2.14.1, “Loose index scan”
Section 7.2.10, “Nested-Loop Join Algorithms”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 7.2.5, “Range Optimization”
Section 7.2.5.1, “The Range Access Method for Single-Part Indexes”

ref

Section 7.4.6, “MyISAM Index Statistics Collection”
Section 7.2.16, “Optimizing IN/=ANY Subqueries”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 13.8, “The MERGE Storage Engine”

ref_or_null

Section 7.2.8, “IS NULL Optimization”
Section 7.2.16, “Optimizing IN/=ANY Subqueries”
Section 7.2.1, “Optimizing Queries with EXPLAIN

system

Section 12.2.8, “SELECT Syntax”
Section 17.7.5.1, “MySQL Cluster — Messages in the Cluster Log”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 7.2.5.1, “The Range Access Method for Single-Part Indexes”

unique_subquery

Section 7.2.16, “Optimizing IN/=ANY Subqueries”
Section 7.2.1, “Optimizing Queries with EXPLAIN
Section 12.2.9.10, “Optimizing Subqueries”