weejar zhang

By default, RMAN creates all backups as backup sets, on tape or on disk. You can change the default backup type for disk backups to be image copies using the CONFIGURE command. Backups to tape can only be backup sets.

接上一篇，

如果丢失数据库默认表空间的任一数据文件，数据库会不会shutdown?

Your database is having two control files, three redo log file groups with two members in each group. Failure of which file would cause an instance to shut down

SQL> show parameter recy NAME TYPE VALUE ———————————— ———– —————————— buffer_pool_recycle string db_recycle_cache_size big integer 0 recyclebin string on SQL> alter system set recyclebin=off 2 ; System altered. SQL> show user USER is “SYS” SQL> conn anbob/anbob Connected. SQL> create table testdrop(id integer); Table created. SQL> desc testdrop Name Null? Type —————————————– ——– —————————- ID … Read more

flashback query 可以闪回以前的数据行，但不可以闪回alter table修改前的表结构,这点在11G推出的闪回表空间是一样的…

Identify the two tablespaces whose data files are so critical that only a closed recovery is possible. (Choose two.)