Oracle sql 실행 효율 향상 에 대한 소감 제안

 
-->FROM            ,                

-->  WHERE                  

-->ORACLE  '*'      

-->DELETE  rollback segment        ，    TRUNCATE 

-->COMMIT   :1.rollback segment 
2.          
3.redo log buffer 

--> Alias     Column           

-->ORACLE  sql                    

-->       NOT                

-->                         

-->  '>=',   '>' 

-->where   '!='、'||'、'+'         

-->IN     ,IN                

-->EXIST       

-->       ,UNION OR     

-->IS NULL      

-->DISTINCT,UNION,MINUS,INTERSECT,ORDER BY    SORT  ,      

-->                 

-->    UNION ALL  UNION 

-->   TO_NUMBER()             。 

-->              ：col = '123'     col = 123,       TO_NUMBER(EMP_TYPE)=123 

-->             ：HAVING                       WHERE      HAVING 

-->       ,INSERT,DELETE,UPDATE          I/O 

-->        ：ALTER INDEX <INDEXNAME> REBUILD <TABLESPACENAME> [ONLINE]