Binary Search in Standard Tables
If you read entries from standard tables using a key other than the default key, you can use a binary search instead of the normal linear search. To do this, include the addition BINARY SEARCH in the corresponding READstatements.
READ TABLE itab WITH KEY k1 = f1 ... kn = fn result BINARY SEARCH.
The standard table must be sorted in ascending order by the specified search key. The BINARY SEARCH addition means that you can access an entry in a standard table by its key as quickly as you would be able to in a sorted table.
REPORT demo_int_tables_read_index_bin.
DATA: BEGIN OF line, col1 TYPE i, col2 TYPE i, END OF line.
DATA itab LIKE STANDARD TABLE OF line.
DO 4 TIMES. line-col1 = sy-index. line-col2 = sy-index ** 2. APPEND line TO itab.ENDDO.
SORT itab BY col2.
READ TABLE itab WITH KEY col2 = 16 INTO line BINARY SEARCH.
WRITE: 'SY-SUBRC =', sy-subrc.
The list output is:
SY-SUBRC = 0
The program fills a standard table with a list of square numbers and sorts them into ascending order by field col2 . The READ statement uses a binary search to look for and find the line in the table where col2 has the value 16.