EXPLAIN shows information about the database: the number of tables; how tables are joined; how data is looked up (full table scan, full index scan or partial index scan); the presence of subqueries, sorts, and unions; DISTINCT and WHERE clauses are used; indexes used and their length (longer index – longer search); number of records examined

iLAB OVERVIEW Scenario and Summary EXPLAIN shows information about the database: the number of tables; how tables are joined; how […]