The Data Guard Broker PREPARE DATABASE FOR DATA GUARD command configures a database to be used as a Primary Database in a Data Guard Broker configuration. It enables and sets a number of database parameters like LOG_BUFFER, DG_BROKER_START, STANDBY_FILE_MANAGEMENT, DB_BLOCK_CHECKSUM etc. It also enables FLASHBACK and ARCHIVELOG for the database and creates the Standby Redo […]
In earlier versions the RMAN DUPLICATE database command was a push-based method. One of the new features in Oracle 12c is that it has been changed to a pull-based method which has many advantages. Let us note the difference between the two methods. In the earlier push-based method, the source database transfers the required database […]
Some times we need to have an exact replica of the production database data to urgently test an issue encountered in production. If the production database is very large having a clone process running on the production server or taking a fresh full database backup just for the clone is also not desirable as well […]
In Oracle 12c we can now transport data across platforms using full as well as incremental backup sets. The use of RMAN Incremental backups can significantly reduce overall application downtime during cross-platform data migration and will be useful in any 11g to 12c future upgrades. In this example we look at migrating data from an […]
This note examines how to create an Oracle 12.1.0 physical standby Active Data Guard database using the RMAN DUPLICATE FROM ACTIVE command. We will be creating the data guard configuration in a 12c Container Database. Remember – in 12c Data Guard is set up at the Container level and not the individual Pluggable database level […]
One of the good new features in Oracle 12c is the ability to restore a single table or a single partition of a partitioned table from an RMAN backup via the RECOVER TABLE command. Prior to 12c restoring a table was a long drawn out and difficult affair. So when may we use this fearure? […]
This note explains the procedure used to restore an Oracle Suggested Strategy incremental backup on another server. This is useful when we have to do periodic testing of disaster recovery procedures where we simulate a scenario when the complete database server has crashed and a new server has been provisioned. But let us assume that […]
Let us look at some backup and recovery scenarios pertaining to the SPFIILE. The SPFILE is a small but very important file and if we lose the spfile, we cannot start the database even if all the other database files are present and intact. So in my opinion, it is quite an important thing to […]
Scenario: 1) We want to restore the production database which is running on two-node RAC environment in a test non-RAC environment 2) We want to restore the backup residing on ASM disk groups in a non-ASM file system. Note: The production database orcl has two instances named orcl1 and orcl2. The database will be restored […]
This note describes the procedure used to perform a 32 bit to 64 bit conversion of an 11.2.0.3 database on the Linux platform. The RMAN CONVERT DATABASE command is used to automate the movement of an entire database from one platform (the source platform) to another (the destination platform). This is provided that the source […]
The 11g Data Recovery Advisor is part of the 11g database health checking framework and diagnoses persistent data failures and not only presents options to repair and fix the problem but also can execute the repair and recovery process at our request. The Repair Advisor can take away lot of the stress associated with peforming […]
A common DBA task is to perform regular clones and database refreshes of the production database for the purpose of setting up training or test or development environments. If we are having a physical standby Data Guard environment, then we can easily offload the potentially I/O and CPU intensive backup process required for creating these […]
Prior to Oracle 10g, the redo log files generated after opening the database with RESETLOGS could not be used with the backups taken before the RESETLOGS was performed. Therefore, whenever a resetlogs was done, it was important to take an immediate full database backup, since all previous backups became invalid. Just to recap, a RESETLOGS […]
I have added a few more RMAN recovery scenarios which I have come across recently and may be faced by others – so thought I’d share those with the community. The first relates to a case where we need to create a replica of a production database on a test or development environment and we […]
Purpose This note explains the procedure of creating a Physical Standby database using 11g RMAN DUPLICATE FROM ACTIVE DATABASE feature which is now available in 11g Release 1 onwards. This enables us to create a physical standby database without having to take a backup of the primary database as a prerequisite step. Environment Primary Database […]
By using Optimized Incremental Backup to disk backup strategy, an up to date copy of the database is always available on disk. In the event of a failure, the SWITCH command will point the controlfile to the backup of the datafiles that are present on disk. In this way, we can significantly reduce the downtime […]
Backup and Recovery best practices dictate that we must use a RMAN recovery catalog and also have the controlfile AUTOBACKUP enabled. If we do not do either and we lose all the controlfiles, we cannot restore the controlfiles even if we have taken a backup to tape as shown in the case below. We will […]
Scripts to check backup status and timings of database backups – This script will be run in the database, not the catalog. Login as sysdba – This script will report on all backups – full, incremental and archivelog backups – col STATUS format a9 col hrs format 999.99 select SESSION_KEY, INPUT_TYPE, STATUS, to_char(START_TIME,’mm/dd/yy hh24:mi’) start_time, […]
The validate command for backup and restore is useful to confirm that backup and restoration is posssible and valid without actually backing up or restoring datafiles. We can validate the restore of a spfile,controlfile,archivelog or even the whole database backup. The following example enables us to specify a point in time upto which we need […]
The following notes will illustrate the steps required to recover from a number of common failure scenarios that a DBA could possibly face in his career. RMAN Restore on another machine with different file system- same database name RMAN duplicate database on the same host Loss Of All Files – Disaster Recovery Incomplete Recovery (until […]
