id,summary,reporter,owner,description,type,status,component,version,severity,resolution,keywords,cc,stage,has_patch,needs_docs,needs_tests,needs_better_patch,easy,ui_ux 22125,Unnecessary creation of index for ManyToManyField,tbhtan3@…,bwreilly,"Suppose I have the following model: {{{ class Food(models.Model): restaurants = models.ManyToManyField(Restaurant) }}} The following table is created: {{{ CREATE TABLE ""main_food_restaurants"" ( ""id"" integer NOT NULL PRIMARY KEY, ""food_id"" integer NOT NULL, ""restaurant_id"" integer NOT NULL, UNIQUE (""food_id"", ""restaurant_id"") ) }}} and the indexes: {{{ CREATE INDEX ""main_food_restaurants_0899c464"" ON ""main_food_restaurants"" (""food_id""); CREATE INDEX ""main_food_restaurants_be4c8f84"" ON ""main_food_restaurants"" (""restaurant_id""); }}} Notice that the single index on food_id is not needed due to the unique index `(food_id, restaurant_id)`. ",Cleanup/optimization,new,"Database layer (models, ORM)",master,Normal,,db-indexes,emorley@… Phil Krylov,Accepted,1,0,0,1,0,0