like standard table of、type standard table of、TYPE HASHED TABLE

like standard table of和type standard table of有什么区别

1.TYPE后面跟随的只能是某种类(型),

2.而LIKE后面可以跟实例对象,参照结构体对象生成内表时只能用LIKE,不能用TYPE,因为结构体对象不是类型,只是一种实例对象,参照结构类型生成内表时可以用LIKE也可以用TYPE.
3.其中通过LIKE定义的内表直接拥有参照结构类型的元素结构,

4.而通过TYPE定义的内表只能间接拥有被参照结构类型的元素结构,结构类型不能作为内表的工作区,只有结构体对象才可以.

 

TYPE STANDARD TABLE OF和TYPE HASHED TABLE区别

1.The meaning of TYPE STANDARD TABLE OF and TYPE TABLE OF is exactly the same.

2.A table of TYPE HASHED TABLE creates an internal table that is represented using an internal HASH algorithm, allowing reads to the table where the cost is (by approximation) independent from the size of the table. Using this type of table is good when you have large data-sets with a lot of reads, but comparatively few writes. When declaring a hash table you have to also declare a UNIQUE KEY, as the HASH algorithm is dependent on this.

 

 

TYPES : BEGIN OF ST_AUTH,
   WERKS TYPE T001W-WERKS ,
 END OF ST_AUTH .

DATA T_AUTH TYPE STANDARD TABLE OF ST_AUTH .
DATA W_AUTH LIKE LINE OF T_AUTH .