LOOP vs parallel cursor LOOP performance?

Question

I'm interviewing for a job, and on the test they sent me they provided the following image of 2 ABAP loops on an internal table, and asked which loop will execute faster:

After checking heavily on the internet I came to this 2 different outcomes:

• on the one hand, as for what I found online, the "WHERE" statement is faster than the logical if statement, due to the fact that it directly processes the records satisfying the condition.
• on the other hand, it seems as the 2 loops are doing different things and that the right loop is basically jumping ahead whenever WA2-K != WA1-K, so I believe execution is very dependent on the provided tables.

Am I missing something? is there an obvious 1 answer to this question?

Answer 1

Your screenshot comes from the program RSHOWTIM (or SE38 > menu Environment > Examples -> Performance examples), which is available in all ABAP-based software.

The two algorithms are doing exactly the same thing (*), but one is more performing than the other. SY-TABIX is the line number of the last iterated line inside the LOOP AT block (providing that it's a standard or sorted table).

(*) see Gert comment

The full screen is this one (in ABAP 7.52):

NB: you could install an ABAP trial system on your computer if you need to train. Or you can use Cloud trials (you have then to pay for the network/disk usage).