Oracle的熱備份

一、 什么是熱備份

　　　　熱備份也叫聯機備份，它是指數據庫處於open狀態下，對數據庫的數據文件、控制文件、參數文件、密碼文件等進行一系列備份操作（其中數據文件是必須備份的）。

　　　　它要求數據庫處在歸檔模式下。

　　　　在熱備時，是可以進行DML操作的

二、 熱備的過程

　　　　凍結塊頭-->控制SCN在備份時不發生變化，並產生檢查點，發生在置於備份狀態的時候

    　　   進行物理拷貝

    　　  解凍塊頭-->讓SCN可以變化(當對SCN解凍后，系統會自動更新SCN至最新的狀態)

三、 需要注意的問題

　　由於數據文件處於備份狀態時重做日志后台進程要將這些文件的所有的變化數據塊寫到重做日志文件中，這對重做日志緩沖區和重做日志文件的壓力都增大了，所以需要注意幾下加點：

• 　　重做日志緩沖區和重做日志文件適當增大
• 　　在聯機備份時，每次只備份一個表空間
• 　　在DML最少的時候做備份

四、 幾種不同的熱備方式

1、 基於表空間的熱備

　　--查詢表空間的名字和狀態

SQL> select file_id,tablespace_name,status from dba_data_files; 

   FILE_ID TABLESPACE_NAME          STATUS
---------- ------------------------------ ---------
     4 USERS              AVAILABLE
     3 UNDOTBS1              AVAILABLE
     2 SYSAUX              AVAILABLE
     1 SYSTEM              AVAILABLE
     5 COSTCTL_TBS              AVAILABLE
     6 DEV_DATA              AVAILABLE
     7 PDMS_DATA              AVAILABLE

已選擇7行。

　　--開始備份，將會

SQL> alter tablespace PDMS_DATA  begin backup;

表空間已更改。

　　--拷貝數據文件到指定的備份磁盤上

SQL> host cp /opt/oracle/app/oradata/pdms/PDMS_DATA.dbf /u03/backup/hotbak

　　--查看所有數據文件的備份狀態

SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME
---------- ------------------ ---------- --------------
     1 NOT ACTIVE               0
     2 NOT ACTIVE               0
     3 NOT ACTIVE               0
     4 NOT ACTIVE               0
     5 NOT ACTIVE               0
     6 NOT ACTIVE               0
         7 ACTIVE               12657642 15-12月-16

　　--將表空間重新設置為非備份狀態

SQL> alter tablespace PDMS_DATA end backup;

表空間已更改。

　　--查看備份狀態

SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME
---------- ------------------ ---------- --------------
     1 NOT ACTIVE               0
     2 NOT ACTIVE               0
     3 NOT ACTIVE               0
     4 NOT ACTIVE               0
     5 NOT ACTIVE               0
     6 NOT ACTIVE               0
         7 NOT ACTIVE           12657642 15-12月-16

已選擇7行。

 

2. 基於數據庫的熱備

　　alter database begin backup;

      拷貝所有的datafile到備份目錄

      alter database end backup;

 

3. 控制文件的熱備

　 alter database backup controlfile to '<dir>' [reuse];          --控制文件的完整備份

    alter database backup controlfile to trace as '<dir>'  --用於創建控制文件的語句，丟失了部分信息，可以直接查看

SQL> alter database backup controlfile to '/u03/backup/hotbak/control01.ctl';

數據庫已更改。

SQL> alter database backup controlfile to trace as '/u03/backup/hotbak/control02.ctl';

數據庫已更改。

查control02.ctl

-- The following are current System-scope REDO Log Archival related
-- parameters and can be included in the database initialization file.
--
-- LOG_ARCHIVE_DEST=''
-- LOG_ARCHIVE_DUPLEX_DEST=''
--
-- LOG_ARCHIVE_FORMAT=%t_%s_%r.dbf
--
-- DB_UNIQUE_NAME="dbsrv1"
--
-- LOG_ARCHIVE_CONFIG='SEND, RECEIVE, NODG_CONFIG'
-- LOG_ARCHIVE_MAX_PROCESSES=3
-- STANDBY_FILE_MANAGEMENT=MANUAL
-- STANDBY_ARCHIVE_DEST=?/dbs/arch
-- FAL_CLIENT=''
-- FAL_SERVER=''
--
-- LOG_ARCHIVE_DEST_3='LOCATION=/u03/ARCHLOG/'
-- LOG_ARCHIVE_DEST_3='OPTIONAL REOPEN=300 NODELAY'
-- LOG_ARCHIVE_DEST_3='ARCH NOAFFIRM NOEXPEDITE NOVERIFY SYNC'
-- LOG_ARCHIVE_DEST_3='REGISTER NOALTERNATE NODEPENDENCY'
-- LOG_ARCHIVE_DEST_3='NOMAX_FAILURE NOQUOTA_SIZE NOQUOTA_USED NODB_UNIQUE_NAME'
-- LOG_ARCHIVE_DEST_3='VALID_FOR=(PRIMARY_ROLE,ONLINE_LOGFILES)'
-- LOG_ARCHIVE_DEST_STATE_3=ENABLE
--
-- LOG_ARCHIVE_DEST_2='LOCATION=/u02/ARCHLOG/'
-- LOG_ARCHIVE_DEST_2='OPTIONAL REOPEN=300 NODELAY'
-- LOG_ARCHIVE_DEST_2='ARCH NOAFFIRM NOEXPEDITE NOVERIFY SYNC'
-- LOG_ARCHIVE_DEST_2='REGISTER NOALTERNATE NODEPENDENCY'
-- LOG_ARCHIVE_DEST_2='NOMAX_FAILURE NOQUOTA_SIZE NOQUOTA_USED NODB_UNIQUE_NAME'
-- LOG_ARCHIVE_DEST_2='VALID_FOR=(PRIMARY_ROLE,ONLINE_LOGFILES)'
-- LOG_ARCHIVE_DEST_STATE_2=ENABLE
--
-- LOG_ARCHIVE_DEST_1='LOCATION=/u01/ARCHLOG/'
-- LOG_ARCHIVE_DEST_1='MANDATORY REOPEN=300 NODELAY'
-- LOG_ARCHIVE_DEST_1='ARCH NOAFFIRM NOEXPEDITE NOVERIFY SYNC'
-- LOG_ARCHIVE_DEST_1='REGISTER NOALTERNATE NODEPENDENCY'
-- LOG_ARCHIVE_DEST_1='NOMAX_FAILURE NOQUOTA_SIZE NOQUOTA_USED NODB_UNIQUE_NAME'
-- LOG_ARCHIVE_DEST_1='VALID_FOR=(PRIMARY_ROLE,ONLINE_LOGFILES)'
-- LOG_ARCHIVE_DEST_STATE_1=ENABLE

--
-- Below are two sets of SQL statements, each of which creates a new
-- control file and uses it to open the database. The first set opens
-- the database with the NORESETLOGS option and should be used only if
-- the current versions of all online logs are available. The second
-- set opens the database with the RESETLOGS option and should be used
-- if online logs are unavailable.
-- The appropriate set of statements can be copied from the trace into
-- a script file, edited as necessary, and executed when there is a
-- need to re-create the control file.
--
--     Set #1. NORESETLOGS case
--
-- The following commands will create a new control file and use it
-- to open the database.
-- Data used by Recovery Manager will be lost.
-- Additional logs may be required for media recovery of offline
-- Use this only if the current versions of all online logs are
-- available.

-- After mounting the created controlfile, the following SQL
-- statement will place the database in the appropriate
-- protection mode:
--  ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE

STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "DBSRV1" NORESETLOGS  ARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 100
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/opt/oracle/app/oradata/dbsrv1/redo01.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 2 '/opt/oracle/app/oradata/dbsrv1/redo02.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 3 '/opt/oracle/app/oradata/dbsrv1/redo03.log'  SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE

DATAFILE
  '/opt/oracle/app/oradata/dbsrv1/system01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/sysaux01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/undotbs01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/users01.dbf',
  '/opt/oracle/app/oradata/costctl/COSTCTL_TBS.dbf',
  '/opt/oracle/app/oradata/dbsrv1/DEV_DATA.DBF',
  '/opt/oracle/app/oradata/pdms/PDMS_DATA.dbf'
CHARACTER SET AL32UTF8
;

-- Commands to re-create incarnation table
-- Below log names MUST be changed to existing filenames on
-- disk. Any one log file from each branch can be used to
-- re-create incarnation records.
-- ALTER DATABASE REGISTER LOGFILE '/u03/ARCHLOG/1_1_694916203.dbf';
-- ALTER DATABASE REGISTER LOGFILE '/u03/ARCHLOG/1_1_917304775.dbf';
-- Recovery is required if any of the datafiles are restored backups,
-- or if the last shutdown was not normal or immediate.
RECOVER DATABASE

-- All logs need archiving and a log switch is needed.
ALTER SYSTEM ARCHIVE LOG ALL;

-- Database can now be opened normally.
ALTER DATABASE OPEN;

-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/opt/oracle/app/oradata/dbsrv1/temp01.dbf'
     SIZE 38797312  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M;
ALTER TABLESPACE COSTCTL_TBS_TEMP ADD TEMPFILE '/opt/oracle/app/oradata/costctl/COSTCTL_TBS_temp.dbf'
     SIZE 524288000  REUSE AUTOEXTEND ON NEXT 8192  MAXSIZE 32767M;
ALTER TABLESPACE PDMS_DATA_TEMP ADD TEMPFILE '/opt/oracle/app/oradata/pdms/PDMS_DATA_TEMP.dbf'
     SIZE 524288000  REUSE AUTOEXTEND ON NEXT 8192  MAXSIZE 32767M;
-- End of tempfile additions.
--
--     Set #2. RESETLOGS case
--
-- The following commands will create a new control file and use it
-- to open the database.
-- Data used by Recovery Manager will be lost.
-- The contents of online logs will be lost and all backups will
-- be invalidated. Use this only if online logs are damaged.

-- After mounting the created controlfile, the following SQL
-- statement will place the database in the appropriate
-- protection mode:
--  ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE

STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "DBSRV1" RESETLOGS  ARCHIVELOG
    MAXLOGFILES 16
    MAXLOGMEMBERS 3
    MAXDATAFILES 100
    MAXINSTANCES 8
    MAXLOGHISTORY 292
LOGFILE
  GROUP 1 '/opt/oracle/app/oradata/dbsrv1/redo01.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 2 '/opt/oracle/app/oradata/dbsrv1/redo02.log'  SIZE 50M BLOCKSIZE 512,
  GROUP 3 '/opt/oracle/app/oradata/dbsrv1/redo03.log'  SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE

DATAFILE
  '/opt/oracle/app/oradata/dbsrv1/system01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/sysaux01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/undotbs01.dbf',
  '/opt/oracle/app/oradata/dbsrv1/users01.dbf',
  '/opt/oracle/app/oradata/costctl/COSTCTL_TBS.dbf',
  '/opt/oracle/app/oradata/dbsrv1/DEV_DATA.DBF',
  '/opt/oracle/app/oradata/pdms/PDMS_DATA.dbf'
CHARACTER SET AL32UTF8
;

-- Commands to re-create incarnation table
-- Below log names MUST be changed to existing filenames on
-- disk. Any one log file from each branch can be used to
-- re-create incarnation records.
-- ALTER DATABASE REGISTER LOGFILE '/u03/ARCHLOG/1_1_694916203.dbf';
-- ALTER DATABASE REGISTER LOGFILE '/u03/ARCHLOG/1_1_917304775.dbf';
-- Recovery is required if any of the datafiles are restored backups,
-- or if the last shutdown was not normal or immediate.
RECOVER DATABASE USING BACKUP CONTROLFILE

-- Database can now be opened zeroing the online logs.
ALTER DATABASE OPEN RESETLOGS;

-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/opt/oracle/app/oradata/dbsrv1/temp01.dbf'
     SIZE 38797312  REUSE AUTOEXTEND ON NEXT 655360  MAXSIZE 32767M;
ALTER TABLESPACE COSTCTL_TBS_TEMP ADD TEMPFILE '/opt/oracle/app/oradata/costctl/COSTCTL_TBS_temp.dbf'
     SIZE 524288000  REUSE AUTOEXTEND ON NEXT 8192  MAXSIZE 32767M;
ALTER TABLESPACE PDMS_DATA_TEMP ADD TEMPFILE '/opt/oracle/app/oradata/pdms/PDMS_DATA_TEMP.dbf'
     SIZE 524288000  REUSE AUTOEXTEND ON NEXT 8192  MAXSIZE 32767M;
-- End of tempfile additions.
--

 

4. 參數文件的熱備

　　create pfile from spfile ;

      create pfile = '<dir>' from spfile;

SQL> create pfile = '/u03/backup/hotbak/initdbsrv1.ora' from spfile;

文件已創建。

 

5. 臨時表空間的數據文件、日志文件不需要備份

 

五、熱備腳本

基於表空間的熱備（推薦使用這種方式）

vim hotbak.sql

set feedback off
set heading off
set verify off
set trimspool off
set pagesize 0
set linesize 200
define dir = '/u03/backup/hotbak'
define script = '/tmp/hotbak_tb.sql'
ho rm &script
ho rm &dir/*
spool &script
select 'alter tablespace '|| tablespace_name ||' begin backup ;' ||
 chr(10)||'ho cp ' || file_name || ' &dir ' ||
 chr(10)||'alter tablespace '|| tablespace_name || ' end backup;'
 from dba_data_files order by tablespace_name;
spool off
start &script
alter database backup controlfile to '&dir/controlbak.ctl';
create pfile = '&dir/initdbsrv1.ora' from spfile;

  其中char(10)表示換行,紅色部分需要自行修改

SQL> start hotbak.sql;  --執行該腳本即可對數據庫基於表空間進行熱備

 

基於數據庫（數據文件）的熱備

vim hotbak.sql

set feedback off
set heading off
set verify off
set trimspool off
set pagesize 0
set linesize 200
define dir = '/u03/backup/hotbak'
define script = '/tmp/hotbak_tb.sql'
ho rm &script
ho rm &dir/* 
spool &script
select 'alter tablespace '|| tablespace_name ||' begin backup ;' ||
 chr(10)||'ho cp ' || file_name || ' &dir ' ||
 chr(10)||'alter tablespace '|| tablespace_name || ' end backup;'
 from dba_data_files order by tablespace_name;
spool off
start &script
alter database backup controlfile to '&dir/controlbak.ctl';
create pfile = '&dir/initdbsrv1.ora' from spfile;