A.control_filesB.memory_targetC.db_nameD.db_block_size
A.沒有活動事務的block,一定不會出現(xiàn)ORA-01555B.當undo segment被刪除時,一定會報ORA-01555C.塊清除時匹配不到比snap_scn小的commit scn時,一定會報ORA-01555D.當undo段頭事務表slot被重用時,一定會報ORA-01555
A.rankB.row_numberC.dense_rank