Select count(*) is faster then Select single

SE30 analysis:

SELECT count(*) FROM bkpf WHERE bukrs = s_trans-bukrs AND
belnr = s_trans-belnr AND
gjahr = s_trans-gjahr AND
stblg = space.

vs

SELECT single * FROM bkpf WHERE bukrs = s_trans-bukrs AND
belnr = s_trans-belnr AND
gjahr = s_trans-gjahr AND
stblg = space.