I was working on a minor problem recently where controlfile autobackups were written to the wrong location during rman backups. Taking controlfile autobackups is generally a good idea, even if you configure controlfile backups yourself. Autobackups also include an spfile backup, though not critical for restore, is still convenient to have. And autobackups are taken not only after backups, but more importantly every time you change the physical structure of your database, like adding or (more...)
Oracle Cloud – DBaaS instance down for no apparent reason – (how archive log mode and storage shortage forced the instance to its knees)
My Oracle Public Cloud DBaaS instance did not respond. On closer investigation, it turned out to be down. Mounting the database ended with an ORA-3113 End of Communication Channel. Investigation of the startup log and the database alerts indicated that no new archive log files could be created. The DBaaS instance is in archive log mode – and has created quite a chunk of archive log files over the last few months – now causing (more...)
The Oracle Database Cloud Service allows for backup of an Oracle Database to the Oracle Cloud using Rman. Enterprise Manager 13c provides a very easy way to configure Oracle Database Backup Cloud Service. This post will walk you thru setup of the Oracle Database Backup Cloud service as well as running backups from EM.
There is a new menu Item to configure the Database Backup Cloud Service (DBCS) in the Backup & Recovery Drop down.
Since 11.1 RMAN has had a silent new feature – RMAN Backup Undo Optimization. This feature will exclude undo from committed transactions (after undo_retention time has also passed) from backups, possibly making the undo tablespace backup much smaller. The documentation just says that it will work for disk backups and Oracle Secure Backup tape backups. Since lately I’m been playing around a lot with image copy backups I wanted to find out if this (more...)
I am going to write a series of blogs starting with this one to discuss the fundamental architecture of the Recovery Appliance and discuss the business case as well as deployment and operational strategies around the Recovery Appliance.
So Lets start with why an Appliance. Oracle (more...)
Corruption happened because we forgot to enable force logging.
As this was new dev database there wasn’t backup, but maybe not everything was lost. If only corrupted segments are indexes we could easily rebuild them.
Then I’ve learnt (more...)
On a T5 Super Cluster (running 126.96.36.199) I was creating a cascaded standby from an already functional standby using RMAN DUPLICATE and it errored out with
ORA-01671: control file is a backup, cannot make a standby control file
A quick search reveals that it is bug 11715084 that affects most of the 11.x versions except 188.8.131.52. There is a one off patch available for most of the versions (more...)
For our backup strategy we are using incrementally updated image copies on most Oracle databases. This method can save a lot of time during restore operations, since you don’t need to restore full backup and then apply all the incremental backups, you can either restore the full backup directly (or skip restore operation and switch over to the image copy directly). At the same time, taking backups is as easy and fast as taking incremental (more...)
I had the pleasure of rebuilding an Exadata rack for a customer a while back, and it provided a pretty good refresher in backup and recovery for me. As DBAs, we back up databases all the time, but the restores are performed much less frequently. In the case of this rack, there were several databases across multiple ASM diskgroups. One of the goals of the rebuild was to consolidate all of the databases into a (more...)
But what if you have Standard Edition database:
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database flashback on;
alter database flashback on
ERROR at line 1:
ORA-00439: feature not enabled: Flashback Database
In Standard Edition you don’t have Flashback Database feature, but you can still create restore points and (more...)
All of these RMAN features are available on Oracle versions before 12c.
In this post I will use slightly different approach - using online relocation of data files into ASM.
Using the RMAN command "validate (more...)
connect auxiliary /;
duplicate database to testdb
backup location '$BACKUPDIR'
One important difference between the demo database and this new test database is that the original demo database (more...)
It's great that we have so big and active Oracle community.
Today I noticed mail from Oracle-L list where someone asked for help with recovery after overwriting production controlfiles. Check Oracle-L for more info.
It reminded me that (more...)