发现ORACLE大部分进程在执行以下语句,造成数据库服务器,效率极低。请高手指教,以下语句为何意,有何解决方法,谢!
分不够可加!
SELECT ROWNUM recno, u.*
    FROM (SELECT *
              FROM (SELECT catalog_name, schema_name, table_name, index_name, 
                           column_name, column_position, max(pkey_name)
                           pkey_name, sum(index_type) index_type, sort_order, 
                           filter
                        FROM (SELECT :sys_b_00 catalog_name, 
                                     index_owner schema_name, i.table_name, 
                                     i.index_name, column_name, column_position, 
                                     :sys_b_01 pkey_name, decode(i.uniqueness, 
                                     :sys_b_02, :sys_b_03, :sys_b_04)
                                     index_type, :sys_b_05 sort_order, 
                                     :sys_b_06 filter
                                  FROM all_ind_columns b, all_indexes i
                                  WHERE i.table_name LIKE :sys_b_07
                                    AND i.owner = :sys_b_08
                                    AND i.index_name = b.index_name
                                    AND i.owner = b.index_owner
                              UNION 
                              SELECT :sys_b_09 catalog_name, 
                                     i.owner schema_name, i.table_name, 
                                     i.constraint_name index_name, column_name, 
                                     column_position, 
                                     i.constraint_name pkey_name, :sys_b_10
                                     index_type, :sys_b_11 sort_order, 
                                     :sys_b_12 filter
                                  FROM all_ind_columns b, sys.all_constraints i
                                  WHERE i.table_name LIKE :sys_b_13
                                    AND i.owner = :sys_b_14
                                    AND i.constraint_name = b.index_name
                                    AND i.owner = b.index_owner
                                    AND i.constraint_type = :sys_b_15)
                        GROUP BY catalog_name, schema_name, table_name, 
                                 index_name, column_name, sort_order, filter, 
                                 column_position)) u