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哈希表(hash)和排序表(sort)性能比较

石头 4月 13, 2017 性能优化 23,309 views 0

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1, 名词解释

ABAP程序中内表会用到哈希表(hash)和排序表(sort)：

排序表：关键字为 SORTED TABLE, 有一个逻辑索引，按其表关键字升序排序后再进行存储，其访问方式与标准表相同。

哈希表：关键字为 HASHED TABLE, 没有索引，只能通过关键字来访问。系统用哈希算法管理表中的数据，因而其寻址一个数据行的时间和表的行数无关。

2, 例子代码

REPORT ztest_hash_sort.
TABLES:vbak,
       vbap.    "

************************************************************************

**  定义结构类型 Define the structure's type                          **

************************************************************************

TYPES:BEGIN OF ty_result,
        vbeln  TYPE sy-tabix,
        posnr  TYPE vbap-posnr,
        kunnr  TYPE vbak-kunnr,
        name1  TYPE kna1-name1,
        matnr  TYPE vbap-matnr,
        arktx  TYPE vbap-arktx,
        kwmeng TYPE vbap-kwmeng,
        meins  TYPE vbap-meins,
        kbetr  TYPE konv-kbetr,
        netwr  TYPE vbap-netwr,
        waerk  TYPE vbap-waerk,
      END OF ty_result.

************************************************************************

**  定义变量与内表 Define the variants and Internal tables            **

************************************************************************

DATA:gt_hash   TYPE HASHED TABLE OF ty_result WITH UNIQUE KEY vbeln posnr,
     gt_sort   TYPE SORTED TABLE OF ty_result WITH UNIQUE KEY vbeln posnr,
     gs_result TYPE ty_result,
     gv_rows   TYPE sy-tabix.


************************************************************************
**  宏定义 Define the macro                                           **
************************************************************************

DEFINE mcr_range.

  clear &1.
  &1-sign = 'I'.
  &1-option = &2.
  &1-low = &3.
  &1-high = &4.
  append &1.

END-OF-DEFINITION.

************************************************************************

**  选择屏幕 Customize the selection-screen                           **

************************************************************************

SELECTION-SCREEN BEGIN OF BLOCK xavery WITH FRAME TITLE text-001.
PARAMETERS:p_rows TYPE sytabix DEFAULT '100',     "初始化内表的记录数
           p_loop TYPE sytabix DEFAULT '100'.     "读取的次数
SELECTION-SCREEN END OF BLOCK xavery.

************************************************************************
**  执行程序事件 Executing the program's events                       **
************************************************************************

INITIALIZATION.

START-OF-SELECTION.

  PERFORM sub_init_data.
  PERFORM sub_sort_table.
  PERFORM sub_hash_table.

END-OF-SELECTION.

*@---------------------------------------------------------------------*
*@      Form  SUB_INIT_DATA
*@---------------------------------------------------------------------*
*       初始化选择条件
*----------------------------------------------------------------------*

FORM sub_init_data .

  DEFINE mcr_init.

    clear gs_result.
    gs_result-vbeln = sy-index.
    gs_result-kunnr = '100000000'.
    gs_result-matnr = 'A0010312'.

    do 10 times.
      gs_result-posnr = gs_result-posnr + 10.
      insert gs_result into table gt_hash.
      insert gs_result into table gt_sort.
    enddo.

  END-OF-DEFINITION.

  REFRESH:gt_hash,
          gt_sort.

  DO p_rows TIMES.
    mcr_init.
  ENDDO.

ENDFORM.                    " SUB_INIT_DATA

*&---------------------------------------------------------------------*
*&      Form  SUB_HASH_TABLE
*&---------------------------------------------------------------------*
*       测试哈希表的性能
*----------------------------------------------------------------------*

FORM sub_hash_table .

  CLEAR gv_rows.

  DO p_loop TIMES.
    CLEAR gs_result.
    READ TABLE gt_hash INTO gs_result
                       WITH KEY vbeln = sy-index
                                posnr = '000020'.
*                                TRANSPORTING NO FIELDS.

    IF sy-subrc = 0.
      gv_rows = gv_rows + 1.
    ENDIF.

  ENDDO.

  WRITE:/ gv_rows.

ENDFORM.                    " SUB_HASH_TABLE

*&---------------------------------------------------------------------*

*&      Form  SUB_SORT_TABLE

*&---------------------------------------------------------------------*

*       测试排序表的性能

*----------------------------------------------------------------------*

FORM sub_sort_table .

  CLEAR gv_rows.

  DO p_loop TIMES.
    CLEAR gs_result.
    READ TABLE gt_sort INTO gs_result
                       WITH KEY vbeln = sy-index
                                posnr = '000020'
                                BINARY SEARCH.

*                                TRANSPORTING NO FIELDS.

    IF sy-subrc = 0.
      gv_rows = gv_rows + 1.
    ENDIF.

  ENDDO.

  WRITE:/ gv_rows.

ENDFORM.                    " SUB_SORT_TABLE

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REPORT ztest_hash_sort.

TABLES:vbak,

vbap. "

************************************************************************

** 定义结构类型 Define the structure's type **

************************************************************************

TYPES:BEGIN OF ty_result,

vbeln TYPE sy-tabix,

posnr TYPE vbap-posnr,

kunnr TYPE vbak-kunnr,

name1 TYPE kna1-name1,

matnr TYPE vbap-matnr,

arktx TYPE vbap-arktx,

kwmeng TYPE vbap-kwmeng,

meins TYPE vbap-meins,

kbetr TYPE konv-kbetr,

netwr TYPE vbap-netwr,

waerk TYPE vbap-waerk,

END OF ty_result.

************************************************************************

** 定义变量与内表 Define the variants and Internal tables **

************************************************************************

DATA:gt_hash TYPE HASHED TABLE OF ty_result WITH UNIQUE KEY vbeln posnr,

gt_sort TYPE SORTED TABLE OF ty_result WITH UNIQUE KEY vbeln posnr,

gs_result TYPE ty_result,

gv_rows TYPE sy-tabix.

************************************************************************

** 宏定义 Define the macro **

************************************************************************

DEFINE mcr_range.

clear &1.

&1-sign = 'I'.

&1-option = &2.

&1-low = &3.

&1-high = &4.

append &1.

END-OF-DEFINITION.

************************************************************************

** 选择屏幕 Customize the selection-screen **

************************************************************************

SELECTION-SCREEN BEGIN OF BLOCK xavery WITH FRAME TITLE text-001.

PARAMETERS:p_rows TYPE sytabix DEFAULT '100', "初始化内表的记录数

p_loop TYPE sytabix DEFAULT '100'. "读取的次数

SELECTION-SCREEN END OF BLOCK xavery.

************************************************************************

** 执行程序事件 Executing the program's events **

************************************************************************

INITIALIZATION.

START-OF-SELECTION.

PERFORM sub_init_data.

PERFORM sub_sort_table.

PERFORM sub_hash_table.

END-OF-SELECTION.

*@---------------------------------------------------------------------*

*@ Form SUB_INIT_DATA

*@---------------------------------------------------------------------*

* 初始化选择条件

*----------------------------------------------------------------------*

FORM sub_init_data .

DEFINE mcr_init.

clear gs_result.

gs_result-vbeln = sy-index.

gs_result-kunnr = '100000000'.

gs_result-matnr = 'A0010312'.

do 10 times.

gs_result-posnr = gs_result-posnr + 10.

insert gs_result into table gt_hash.

insert gs_result into table gt_sort.

enddo.

END-OF-DEFINITION.

REFRESH:gt_hash,

gt_sort.

DO p_rows TIMES.

mcr_init.

ENDDO.

ENDFORM. " SUB_INIT_DATA

*&---------------------------------------------------------------------*

*& Form SUB_HASH_TABLE

*&---------------------------------------------------------------------*

* 测试哈希表的性能

*----------------------------------------------------------------------*

FORM sub_hash_table .

CLEAR gv_rows.

DO p_loop TIMES.

CLEAR gs_result.

READ TABLE gt_hash INTO gs_result

WITH KEY vbeln = sy-index

posnr = '000020'.

* TRANSPORTING NO FIELDS.

IF sy-subrc = 0.

gv_rows = gv_rows + 1.

ENDIF.

ENDDO.

WRITE:/ gv_rows.

ENDFORM. " SUB_HASH_TABLE

*&---------------------------------------------------------------------*

*& Form SUB_SORT_TABLE

*&---------------------------------------------------------------------*

* 测试排序表的性能

*----------------------------------------------------------------------*

FORM sub_sort_table .

CLEAR gv_rows.

DO p_loop TIMES.

CLEAR gs_result.

READ TABLE gt_sort INTO gs_result

WITH KEY vbeln = sy-index

posnr = '000020'

BINARY SEARCH.

* TRANSPORTING NO FIELDS.

IF sy-subrc = 0.

gv_rows = gv_rows + 1.

ENDIF.

ENDDO.

WRITE:/ gv_rows.

ENDFORM. " SUB_SORT_TABLE

经过SE30测试如下：

小数据量时：排序表则在小数据量的时候更迅速

哈希表在大数据的时候，有优势

以上。

哈希表(hash)和排序表(sort)性能比较

1, 名词解释

2, 例子代码

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1, 名词解释

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