we use various operators in shell scripting for arithmetical and relational operation .unlike other code languages ,a group of characters can be used to relational operators in shell scripting .
In Oracle database, the Flash Recovery Area or FRA is a location on disk where the database can create and manage several kinds of backup and recovery-related files. Main file types are archivelog, flashback log, backups, as well as mirrors for your control files and redo log files. All files in the FRA are Oracle-managed files. Using a Flash Recovery Area simplifies the administration of your database by automatically retaining them for as long as they are needed for restore and recovery activities, and deleting them when they are no longer needed, because the space is needed for another backup and recovery-related purpose. Checking the current usage You can check the configuration by looking at two parameters.The parameters are db_receovery_file_dest and second one db_recovery_file_dest_size . db_receovery_file_dest point to location where the files will be located in Server . FOr normal single Databases this will be any directory for RAC this will be set to a Diskgroup whi
Cold Backup : A cold backup is done when there is no user activity going on with the system. Also called as offline backup, is taken when the database is not running and no users are logged in. all files of the database are copied and no changes during the copy are made. Cold backup can be preformed when Database is in archive mode as well as Non archive log mode . Backup Strategy : Gather all the details of physical files (CRD) files in database . redo log files are online redo log and archived redo log ones . Select file_name,tablespace_name from dba_data_files ; select * from v$controlfile select member from v$logfile ; select name from v$archived_Log ; create pfile from spfile Backup the contol file manually . alter database backup controlfile to trace as '/tmp/coldbackup_controlfile.sql' ; Stop all the DB services (Database ,Listener)on source DB Server. Copy all the files(Datafiles,redologfiles,pfile,contol file backup) from source to backup location
Architecture : Basic Memory Structures Oracle Database includes several memory areas, each of which contains multiple subcomponents. The basic memory structures associated with Oracle Database include: · System global area (SGA) The SGA is a group of shared memory structures, known as SGA components , that contain data and control information for one Oracle Database instance. All server and background processes share the SGA. Examples of data stored in the SGA include cached data blocks and shared SQL areas. · Program global area (PGA) A PGA is a nonshared memory region that contains data and control information exclusively for use by an Oracle process. Oracle Database creates the PGA when an Oracle process starts.One PGA exists for each server process and background process. The collection of individual PGAs is the total instance PGA, or instance PGA . Database initialization parameters set the size of the instance PGA, not individual PGAs. ·
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