Select...Where

SELECT * FORM SPFLI
  WHERE CARRID = ’LH’.
  ...
  ...
  ...
ENDSELECT.

Select...Check

SELECT * FORM SPFLI.
  CHECK SPFLI-CARRID = ’LH’.
  ...
  ...
  ...
ENDSELECT.

In above logic, Select...Where is better than Select...Check because the database can then user an index and system resource load is considerably less.