EXPLAIN форме: Select Expression -> Filter -> Table "STUDENTS" Access By ID -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (full match) -> Table "STUDENTS" Access By ID -> Index "PK_STUDENTS" Full Scan -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) "STUDENTS" Access By ID -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1)