    db_delete_subfield  145 include/dbcs.h int db_delete_subfield(int, int, int);
    db_delete_subfield  139 include/dblocal.h int db_delete_subfield(int, int, int);
    db_delete_subfield 5733 source/db.c       ret = db_delete_subfield(tid, fnum, sfnum);
    db_delete_subfield 6639 source/dbsrv.c    ret = db_delete_subfield(tid, fnum, sfnum);
    db_delete_subfield 2360 source/dbstress.c    ret = db_delete_subfield(tid, fnum, sfnum);