The Problem RMAN archived redolog backups and maintenance commands are deleting files from the Flash Recovery Area (FRA) when needed. For example: RMAN> backup archivelog all delete input; delete obsolete; These commands only delete the files, but not the actual directories when they are empty after the deletion of the files. The Solution When there is an empty subdirectory that is more than 7 days old, they will get purged automatically at the end of controlfile backup. The … [Read more...] about Empty Directories in the Flash Recovery Area (FRA) are not deleted
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Beginners Guide to Flash Recovery Area in Oracle Database
This post discusses the below topics: Benefits of using Flash Recovery Area. Explains how to Create FRA using DB_RECOVERY_FILE_DEST_SIZE and DB_RECOVERY_FILE_DEST Database Files that can reside in Flash Recovery Area. How to Disable FRA What is a Flash Recovery Area? The flash recovery area can be defined as a single, unified storage area that keeps all the database recovery related files and performs recovery activities in an Oracle database. The flash recovery area is the most … [Read more...] about Beginners Guide to Flash Recovery Area in Oracle Database
Oracle Interview Questions – Flash Recovery Area
Naming convention: Oracle 10g: FLASH Recovery Area Oracle 11g: FAST Recovery Area 1. What is a Flash Recovery Area ? The flash recovery area is an Oracle-managed directory, file system, or Automatic Storage Management disk group that provides a centralized disk location for backup and recovery files. All the files you need to completely recover a database from a media failure are part of the Flash Recovery Area. Oracle creates archived logs and flashback logs in the flash recovery area. … [Read more...] about Oracle Interview Questions – Flash Recovery Area
How to Identify Different File types and space used in Flash Recovery Area
Question: How to find out the existence of different types of files and backups available with the usage of space in the Flash Recovery Area? Starting with Oracle 10G Release 2, a new view has been made available: V$FLASH_RECOVERY_AREA_USAGE. V$FLASH_RECOVERY_AREA_USAGE shows the percentage of the total disk quota used by different types of files, and how much space for each type of file can be reclaimed by deleting files that are obsolete, redundant, or already backed up to tape. SQL> … [Read more...] about How to Identify Different File types and space used in Flash Recovery Area
Database Crashed With ORA-19815, ORA-19809, ORA-16038
The Problem Instance terminated due to error 16038 as its not able to archive the log in FRA: ORA-19815: WARNING: db_recovery_file_dest_size of 99614720000 bytes is 100.00% used, and has 0 remaining bytes available. Sat Mar 8 00:57:07 2008 ************************************************************************ You have following choices to free up space from flash recovery area: 1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard, then consider changing RMAN … [Read more...] about Database Crashed With ORA-19815, ORA-19809, ORA-16038
Oracle Database – Measuring Network Capacity using oratcptest
The Basics Oratcptest is a command line tool that runs on two hosts, one in client mode and the other in server mode, to measure network bandwidth and latency between client and server. Oratcptest establishes a TCP connection between the client host and server host and then sends network messages to Oratcptest on the server host. Oratcptest running on the server host writes, if desired, the received messages to disk before replying with the ACK message. Oratcptest could be used as a general … [Read more...] about Oracle Database – Measuring Network Capacity using oratcptest
How to Change Timezone Settings on Exadata
After Oracle Linux 7, Timezone settings method has been changed. Time Zone is configured during the deployment of the Exadata Database Machine. If there is a requirement to change the Time Zone settings after deployment, it requires modifying the following components: Storage Cells Compute Nodes Pre-requirements 1. Stop CRS stack on all the compute nodes: # [GI_HOME]/bin/crsctl stop crs 2. Stop processes on the cells: # cellcli -e alter cell shutdown services all 3. Complete … [Read more...] about How to Change Timezone Settings on Exadata
How To Calculate The Required Network Bandwidth Transfer Of Redo In Data Guard Environments
It's important to transfer and apply redo as fast as possible in a Data Guard environment. To achieve this we have to calculate the required network bandwidth based on the redo generation rate on the primary database. The formula used (assuming a conservative TCP/IP network overhead of 25%) for calculating the network bandwidth is: Required bandwidth = ((Redo rate bytes per sec. / 0.75) * 8) / 1,000,000 = bandwidth in Mbps Measuring the Peak Redo Rate Use the Oracle Statspack utility for … [Read more...] about How To Calculate The Required Network Bandwidth Transfer Of Redo In Data Guard Environments
Managing Rollback/Undo Segments in AUM (Automatic Undo Management)
This post explains how to use the Automatic Undo Management (AUM) feature as compared to the Manual Undo Management related to conventional rollback segments. Managing Rollback/Undo Segments in Automatic Undo Management: The Automatic Undo Management (AUM) feature simplifies and automates the management of undo segments. DBAs have the choice to manage rollback segments as they used to do under older versions of the Oracle RDBMS (Oracle V6 - 8i) or to let the RDBMS do it (available in 9i and … [Read more...] about Managing Rollback/Undo Segments in AUM (Automatic Undo Management)
Oracle Database 12.2 RMAN Cross Platform Tablespace Transport Over Network
Oracle Database 12.1 introduced cross platform data transport using backup-sets. We could perform database/tablespace backups using FOR TRANSPORT/TO PLATFORM clause and restore the same to a different OS Platform. This typically involved 3 steps: create backup on source, copy backup-piece to destination and perform restoration on destination. Starting from 12.2, we can perform cross platform transport of datafiles directly over the network using the FROM SERVICE clause along with the RESTORE … [Read more...] about Oracle Database 12.2 RMAN Cross Platform Tablespace Transport Over Network