场景: 1.数据库开启归档; 2.创建数据文件之后的所有归档日志都在线; 3.数据文件或者表空间没有进行过备份,数据库也没有全库备
场景:
1.数据库开启归档;
2.创建数据文件之后的所有归档日志都在线;
3.数据文件或者表空间没有进行过备份,,数据库也没有全库备份,数据文件异常丢失;
步骤:
创建测试用的表空间:
SQL> create tablespace bbb datafile '/opt/Oracle/oradata/R11203/bbb.dbf' size 100m;
SQL> create table test_b (id number(10)) tablespace bbb;
SQL> insert into test_b values (1);
SQL> commit;
SQL>select name,file# from v$datafile;
NAME FILE#
--------------------------------------------------------------------------------
/opt/oracle/oradata/R11203/aaa.dbf 10
/opt/oracle/oradata/R11203/bbb.dbf 11
11 rows selected.
SQL> host
删除数据文件,模拟异常丢失
bash-4.2$ ls -al /opt/oracle/oradata/R11203/bbb.dbf
-rw-rw---- 1 oracle dba 10493952 Apr 4 09:53 /opt/oracle/oradata/R11203/bbb.dbf
bash-4.2$ mv /opt/oracle/oradata/R11203/bbb.dbf /opt/oracle/oradata/R11203/bbb.dbf.bak
bash-4.2$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Fri Apr 409:55:03 2014
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 -64bit Production
With the Partitioning, OLAP, Data Mining and Real
Application Testing options
SQL> alter tablespace bbb read only;
alter tablespace bbb read only
*
ERROR at line 1:
ORA-01116: error in opening database file 11
ORA-01110: data file 11:
'/opt/oracle/oradata/R11203/bbb.dbf'
ORA-27041: unable to open file
HPUX-ia64 Error: 2: No such file or directory
Additional information: 3
SQL> shutdown immediate;
ORA-01116: error in opening database file 11
ORA-01110: data file 11:
'/opt/oracle/oradata/R11203/bbb.dbf'
ORA-27041: unable to open file
HPUX-ia64 Error: 2: No such file or directory
Additional information: 3
SQL> select status from v$instance;
STATUS
------------
OPEN
SQL> alter system switch logfile;
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL>/
System altered.
SQL> /
System altered.
SQL> /
System altered.
SQL>
停机
SQL> shutdown immediate;
ORA-01116: error in opening database file 11
ORA-01110: data file 11:
'/opt/oracle/oradata/R11203/bbb.dbf'
ORA-27041: unable to open file
HPUX-ia64 Error: 2: No such file or directory
Additional information: 3
SQL> shutdown abort;
ORACLE instance shut down.
把数据库启动到mount状态
SQL> startup mount;
ORACLE instance started.
Total System Global Area 329859072 bytes
FixedSize 2182336 bytes
VariableSize 285213504 bytes
DatabaseBuffers 37748736bytes
RedoBuffers 4714496 bytes
Database mounted.
使用alter database create datafile as ....的方式,重建这个丢失的数据文件:
SQL> alter database create datafile 11;
Database altered.
通过归档日志和redo log对数据文件进行恢复
SQL> recover datafile 11;
Media recovery complete.
SQL> alter database open;
Database altered.
SQL> select * from test_b;
ID
----------
1
在CentOS 6.4下安装Oracle 11gR2(x64)
Oracle 11gR2 在VMWare虚拟机中安装步骤
Debian 下 安装 Oracle 11g XE R2
本文永久更新链接地址:

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MySQL is an open source relational database management system suitable for data storage, management, query and security. 1. It supports a variety of operating systems and is widely used in Web applications and other fields. 2. Through the client-server architecture and different storage engines, MySQL processes data efficiently. 3. Basic usage includes creating databases and tables, inserting, querying and updating data. 4. Advanced usage involves complex queries and stored procedures. 5. Common errors can be debugged through the EXPLAIN statement. 6. Performance optimization includes the rational use of indexes and optimized query statements.

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.

InnoDB's lock mechanisms include shared locks, exclusive locks, intention locks, record locks, gap locks and next key locks. 1. Shared lock allows transactions to read data without preventing other transactions from reading. 2. Exclusive lock prevents other transactions from reading and modifying data. 3. Intention lock optimizes lock efficiency. 4. Record lock lock index record. 5. Gap lock locks index recording gap. 6. The next key lock is a combination of record lock and gap lock to ensure data consistency.

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In database optimization, indexing strategies should be selected according to query requirements: 1. When the query involves multiple columns and the order of conditions is fixed, use composite indexes; 2. When the query involves multiple columns but the order of conditions is not fixed, use multiple single-column indexes. Composite indexes are suitable for optimizing multi-column queries, while single-column indexes are suitable for single-column queries.

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MySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.


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