Backup DBA

What is most important work for DBA’s ?It is Database BACKUP.There are simple three methods which you can use to take database backup.1. COLD backup / Consistent backup / Offline backup2. HOT backup / Inconsistent backup / Online backup / User Managed backup3. RMAN / Inconsistent backup / Online backup / Server Managed backupHow to take COLD backup? ( Database running in NO ARCHIVELOG MODE)1. conn with sysdba user.SQL>shutdown abort;SQL>startup restrict;SQL>shutdown normal;2. take copy of all datafiles,controlfile,redologfiles & parameter files through OS copy command.3. startup database SQL>startup First use "SHUTDOWN IMMEDIATE" command to shutdown database server without "SHUTDOWN ABORT" but if "SHUTDOWN IMMEDIATE" command is HANG then use "SHUTDOWN ABORT" + "STARTUP RESTRICT" + "SHUTDOWN NORMAL"How to take HOT backup?1. conn with sysdba user.SQL> alter database begin backup;2. copy all datafiles except “tempfiles” through OS COPY command.SQL> alter database end backup;SQL> alter system switch logfile;SQL> alter database backup controlfile to ‘OS_PATH’;SQL> create pfile=’OS_PATH\INIT.ORA’ from spfile;How to take RMAN backup?1. cmd> set ORACLE_SID=2. conn with RMAN promptcmd>rman target /RMAN> run{Backup database;Backup archivelog all;}NOTE: above are just simple commands which you follow to take database backup.Except above you can use EXPORT/IMPORT/DATAPUMP to take logical backup of DATABASE TABLES, SCHEMAS, DATABASE.At database levelcmd>exp username/pwd@tns_entry file=OS-PATH FULL=yAt schema levelcmd>exp username/pwd@tns_entry file=OS-PATH OWNER=username(scott)At table levelcmd>exp username/pwd@tns_entry file=OS-PATH TABLES=tablename(emp)