hints

1:索引

 

SELECT /*+ index(e(ENTITYID)) */
 U.REALNAME, E.ENTITYNAME
  FROM TBUSER U, TBENTITY E
 WHERE U.CURRENTENTITYID = E.ENTITYID;

2：基于规则的时候，扫描表的顺序是从右向左

 

SELECT /*+ rule */ U.REALNAME, E.ENTITYNAME
  FROM TBUSER U,TBENTITY E
 WHERE U.CURRENTENTITYID = E.ENTITYID;

 

 

3：全表扫描

SELECT /*+ full(u) full(e)*/
 U.REALNAME, E.ENTITYNAME
  FROM TBUSER U, TBENTITY E
 WHERE U.CURRENTENTITYID = E.ENTITYID
   AND U.USERID = 1;

 

4：