World of Oracle DBA

Types and Authentication of Database that RMAN used to Connect:-------------------------------------------------RMAN client can connect to three types of databases1)The Target Database: The database which need to perform backup and recovery operation that database connection with RMAN client must be the target database. To connect to the target database you must have the SYSDBA privilege.2)The Recovery Catalog Database:The recovery catalog database provides an optional backup store for the RMAN repository. To connect to the recovery catalog database you must need the RECOVERY_CATALOG_OWNER role.3)The Auxiliary Database:RMAN connect to the auxiliary database for performing a specific task such as duplicating a database, transporting tablespaces without taking the making database read-only, or performing tablespace point-in-time recovery.RMAN does not require that you specify the SYSDBA privilege when connecting to a database. Because all RMAN database connections require SYSDBA privileg...

Types and Authentication of Database that RMAN used to Connect:-------------------------------------------------RMAN client can connect to three types of databases1)The Target Database: The database which need to perform backup and recovery operation that database connection with RMAN client must be the target database. To connect to the target database you must have the SYSDBA privilege.2)The Recovery Catalog Database:The recovery catalog database provides an optional backup store for the RMAN repository. To connect to the recovery catalog database you must need the RECOVERY_CATALOG_OWNER role.3)The Auxiliary Database:RMAN connect to the auxiliary database for performing a specific task such as duplicating a database, transporting tablespaces without taking the making database read-only, or performing tablespace point-in-time recovery.RMAN does not require that you specify the SYSDBA privilege when connecting to a database. Because all RMAN database connections require SYSDBA privileg...

Flash recovery area simplifies the ongoing administration of your database by automatically naming recovery-related files, retaining them as long as they are needed for restore and recovery activities, and deleting them when they are no longer needed to restore your database and space is needed for some other backup and recovery-related purpose.To see up flash recovery follow below steps.1)Set up DB_RECOVERY_FILE_DEST_SIZE:SQL> alter system set db_recovery_file_dest_size=2G;2)Decide the area from OS where you will place Flash recovery area.SQL>host mkdir /oradata1/flash_recovery_area3)Set up DB_RECOVERY_FILE_DEST:SQL> alter system set db_recovery_file_dest='/oradata1/flash_recovery_area';The V$RECOVERY_FILE_DEST and V$FLASH_RECOVERY_AREA_USAGE views can help to find out the current location, disk quota, space in use, space reclaimable by deleting files,total number of files, the percentage of the total disk quota used by different types of files, and how much space for...

Some Issues between RMAN Client and Database:---------------------------------------------------•Most RMAN commands take a number of parameters and must end with a semicolon.The exception is some database related command , like STARTUP, SHUTDOWN and CONNECT.•You can write rman commands in a file and then you can run the file. In both ways from command line and within RMAN command prompt you can check.$rman TARGET / @filenameRMAN>@filenameAfter the command file contents have been executed, RMAN displays the following message:RMAN> **end-of-file**•With CHECKSYNTAX you can test some RMAN commands for syntactic correctness without executing them.In both ways from command line and within RMAN command prompt you can check.$rman CHECKSYNTAXRMAN>run your command.From Command Line,rman CHECKSYNTAX @filenameExample:-------------1)Make rmancmdtest file with following entry-bash-3.00$ cat rmancmdtestlist backup;show all;2)From RMAN command prompt checking the syntaxRMAN> @/export/home/...

Flash recovery area simplifies the ongoing administration of your database by automatically naming recovery-related files, retaining them as long as they are needed for restore and recovery activities, and deleting them when they are no longer needed to restore your database and space is needed for some other backup and recovery-related purpose.To see up flash recovery follow below steps.1)Set up DB_RECOVERY_FILE_DEST_SIZE:SQL> alter system set db_recovery_file_dest_size=2G;2)Decide the area from OS where you will place Flash recovery area.SQL>host mkdir /oradata1/flash_recovery_area3)Set up DB_RECOVERY_FILE_DEST:SQL> alter system set db_recovery_file_dest='/oradata1/flash_recovery_area';The V$RECOVERY_FILE_DEST and V$FLASH_RECOVERY_AREA_USAGE views can help to find out the current location, disk quota, space in use, space reclaimable by deleting files,total number of files, the percentage of the total disk quota used by different types of files, and how much space for...

Some Issues between RMAN Client and Database:---------------------------------------------------•Most RMAN commands take a number of parameters and must end with a semicolon.The exception is some database related command , like STARTUP, SHUTDOWN and CONNECT.•You can write rman commands in a file and then you can run the file. In both ways from command line and within RMAN command prompt you can check.$rman TARGET / @filenameRMAN>@filenameAfter the command file contents have been executed, RMAN displays the following message:RMAN> **end-of-file**•With CHECKSYNTAX you can test some RMAN commands for syntactic correctness without executing them.In both ways from command line and within RMAN command prompt you can check.$rman CHECKSYNTAXRMAN>run your command.From Command Line,rman CHECKSYNTAX @filenameExample:-------------1)Make rmancmdtest file with following entry-bash-3.00$ cat rmancmdtestlist backup;show all;2)From RMAN command prompt checking the syntaxRMAN> @/export/home/...

RMAN incremental backups back up only datafile blocks that have changed since aspecified previous backup. Each data block in a datafile contains a system change number (SCN), which is theSCN at which the most recent change was made to the block. During an incrementalbackup, RMAN reads the SCN of each data block in the input file and compares it tothe checkpoint SCN of the parent incremental backup. If the SCN in the input datablock is greater than or equal to the checkpoint SCN of the parent, then RMAN copiesthe block.If you use block change tracking feature then RMAN can refer change tracking file the changed block in the datafile in stead of scanning the whole datafile. I will show in other topic how I can enable block change tracking.Incremental Backup can be either level 0 or level 1 backup.Level 0 Incremental Backup:------------------------------------A level 0 incremental backup is the base backup for subsequent incremental backups.It copies all blocks containing data, backing th...