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Restoring a Datafile Using Archivelogs

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  Suppose a datafile that was recently added to the database is lost for some reasons. In this case, if the archive logs from the time the datafile was created are available, it is possible to recover that datafile. However, as mentioned, this operation has a very strict requirement: “All archive logs from the time the datafile was created must be available.” Below, we will walk through a scenario related to this topic. SQL > archive log list; Database log mode Archive Mode SQL > alter table space USEF_TBS add datafile ‘ / acfs / test2.dbf’ size 10 m; With the following commands, we create a new table that uses space from the new datafile so that after recovery we can verify that no data was lost. SQL > create table usef_tbl1 tablespace usef_tbs as select * from dba_tables where 1 = 2 ; SQL > alter table usef_tbl1 ALLOCATE EXTENT(DATAFILE ‘ / acfs / test2.dbf’ size 5 m); Table altered. SQL > insert into usef_tbl1 select * from ...
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Oracle AI Database 26ai — Managing AWR in Active Data Guard

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  Starting with   Oracle Database 12.2 , generating   AWR reports on an  Active Data Guard (ADG) standby  became possible by using the  Remote Management Framework (RMF) . In this model, AWR data had to be manually transported from the standby to the primary database. Although functional, the setup was complex and required multiple configuration steps, making AWR analysis on physical standby databases operationally challenging for DBAs. With  Oracle Database 26ai , AWR support for  Active Data Guard Standby  databases is fully integrated and enabled by default. AWR snapshots are automatically collected on the ADG standby and transparently transported to the  primary database , without any manual intervention or RMF configuration. By default, snapshots are taken  once per hour , and the  retention period is 8 days . This enhancement allows DBAs to work with AWR on an Active Data Guard standby in the same way as on the primary da...
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Generating AWR Reports in an Active Data Guard using RMF(12.2)

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  As you know, generating AWR reports in an Active Data Guard (ADG) environment is not normally possible. This is logically due to the inability to create snapshots on a database that is in read-only mode. In Oracle 12c Release 2, a solution was introduced, and it became possible to generate AWR reports for ADG databases. In this new feature, a snapshot is first created and workload data from the Data Guard database is stored in a database that is in read-write mode (there is no mandatory requirement to use the primary database for this). After a defined time interval, a second snapshot is created, and the data collection is completed. Finally, the AWR report can be generated. In the following sections, we explain how to perform this process. This capability (remote snapshot) uses the Remote Management Framework (RMF). Before generating the AWR report, several steps are required to create and configure the RMF topology. These steps, along with the other required procedures, are des...
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