EXPLAIN Statement • EXPLAIN  works with  SELECT ,  DELETE ,  INSERT ,  REPLACE , and  UPDATE  statements. In MySQL 8.0.19 and later, it also works with  TABLE  statements. •When  EXPLAIN  is used with an explainable statement, MySQL displays information from the optimizer about the statement execution plan. That is, MySQL explains how it would process the statement, including information about how tables are joined and in which order. For information about using EXPLAIN  to obtain execution plan information, see Section 8.8.2, “EXPLAIN Output Format” . •When  EXPLAIN  is used with  FOR CONNECTION  connection_id  rather than an explainable statement, it displays the execution plan for the statement executing in the named connection. See Section 8.8.4, “Obtaining Execution Plan Information for a Named Connection” . •For explainable statements,  EXPLAIN  produces additional execution plan information that can be displayed using  SHOW WARNINGS . See Section 8.8.3, “Extended EXPLAIN Output Format” . • EXPLAIN  is useful for examining queries involving partitioned tables. See Section 24.3.5, “Obtaining Information About Partitions” . •The  FORMAT  option can be used to select the output format.  TRADITIONAL  presents the output in tabular format. This is the default if no  FORMAT  option is present.  JSON  format displays the information in JSON format. In MySQL 8.0.16 and later,  TREE  provides tree-like output with more precise descriptions of query handling than the  TRADITIONAL  format; it is the only format which shows hash join usage (see Section 8.2.1.4, “Hash Join Optimization” ) and is always used for  EXPLAIN ANALYZE . EXPLAIN  requires the same privileges required to execute the explained statement. Additionally,  EXPLAIN also requires the  SHOW VIEW  privilege for any explained view.  EXPLAIN ... FOR CONNECTION  also requires the  PROCESS  privilege if the specified connection belongs to a different user. With the help of  EXPLAIN , you can see where you should add indexes to tables so that the statement executes faster by using indexes to find rows. You can also use  EXPLAIN  to check whether the optimizer joins the tables in an optimal order. To give a hint to the optimizer to use a join order corresponding to the order in which the tables are named in a  SELECT  statement, begin the statement with  SELECT STRAIGHT_JOIN  rather than just  SELECT . (See Section 13.2.10, “SELECT Statement” .) The optimizer trace may sometimes provide information complementary to that of  EXPLAIN . However, the optimizer trace format and content are subject to change between versions. For details, see MySQL Internals: Tracing the Optimizer. If you have a problem with indexes not being used when you believe that they should be, run  ANALYZE TABLE  to update table statistics, such as cardinality of keys, that can affect the choices the optimizer makes. See Section 13.7.3.1, “ANALYZE TABLE Statement” . Note MySQL Workbench has a Visual Explain capability that provides a visual representation of  EXPLAIN  output. See Tutorial: Using Explain to Improve Query Performance. Obtaining Information with EXPLAIN ANALYZE MySQL 8.0.18 introduces  EXPLAIN ANALYZE , which runs a statement and produces  EXPLAIN  output along with timing and additional, iterator-based, information about how the optimizer’s expectations matched the actual execution. For each iterator, the following information is provided: •Estimated execution cost (Some iterators are not accounted for by the cost model, and so are not included in the estimate.) 2984