I tried to
compare how ABAP filter operator compete with LOOP statement.
1. Classic LOOP statement
On
top of itab t_data that is being looped over into a structure a new itab
t_data1 is generated from the structure. A condition for the LOOP specified as
hardcoded into WHERE part of the LOOP statement.
LOOP AT t_data INTO s_data WHERE ( col_1 = 'AAA' ).
INSERT s_data INTO TABLE t_data1.
ENDLOOP.
2. Filter Operator
A
Filter Operator is used to build the itab t_data2 based on th_data itab. Condition
is specified as hardcoded one in the filter.
DATA(t_data2) = FILTER #( th_data WHERE col_1 = 'AAA' ).
Next, let
assume that we have a multiple conditions for the LOOP so they are stored in a special
itabs.
3. Classic LOOP statement with WHERE
condition as a range
In
a case of the class LOOP statement I leveraged range type of itab. The range (t_filter
itab) is prepared prior the LOOP. Afterwards the range in used in the WHERE
part of the LOOP by IN statement.
t_filter = VALUE #( BASE t_filter ( opt = 'EQ' sign = 'I' low = 'AAA' ) ).
LOOP AT th_data INTO s_data WHERE col_1 IN t_filter.
INSERT s_data INTO TABLE t_data3.
ENDLOOP.
4. FILTER Operator with filter as itab
A
hash itab (th_filter) is prepared with the condition prior the FILTER operator
statement. A new itab (t_data4) is prepared by Filter operator. The Filter operator
uses IN statement to specified the itab with the filter.
th_filter = VALUE #( BASE th_filter ( col_1 = 'AAA' ) ).
DATA(t_data4) = FILTER #( th_data IN th_filter WHERE col_1 = col_1 ).
Conclusion
In
my system based on component SAP_ABA 75, SP04 I achieved the fastest the run no
2. Means Filter operator where the condition was hardcoded.
Few more
remarks:
To
count the no of the itab entries I
used REDUCE (Reduction Operator – part of Iteration expression). The statement
basically goes over all the entries of the itab and adding 1 into n variable as
specified in NEXT statement.
v_count = REDUCE i( INIT n = 0 FOR x_data IN t_data4 NEXT n = n + 1 ).
Yes,
I’m aware that I could do this by lines (a row function) as seen below. However,
I wanted to try more the reduce operator instead.
DATA(v_cnt) = lines( t_data1 )
To
calculate total of figure that is stored in column col_f in all the itabs I
used again Reduction Operator. Just in this case the value of the column col_f is
being added up into n variable.
v_count = REDUCE i( INIT n = 0 FOR x_data IN t_data4 NEXT n = n + x_data-col_f ).
Source code available in my Gitgub gist – zmm_loop_replacement
