Oracle Recovery Manager (RMAN) concepts

Recovery Manager (RMAN) is an Oracle utility that you use to manage the backup, restore, and recovery operations on Oracle database. RMAN has a powerful command language that is independent of the operating system.

Recovery Manager has a command-line interface. Oracle Enterprise Manager (OEM) also provides a graphical user interface for the Recovery Manager. Recovery Manager can be used on databases of Oracle8 or later releases.

RMAN provides several features not available when you make user-managed backups with operating system commands:

  • You can store frequently executed operations as scripts in the database.
  • Using the incremental block-level backup feature you can limit the backup to only those blocks that have changed since the previous backup. This may also reduce the time it takes to perform recovery operations in ARCHIVELOG mode.
  • You can use RMAN to manage the size of backup pieces and save time by parallelizing the backup operation.
  • RMAN operations can be integrated with the scheduling of the operating system to automate backup operations.
  • You can detect block corruption. The information relating to the block corruption that is detected during backup can be obtained by using the V$BACKUP_CORRUPTION and V$COPY_CORRUPTION dynamic views.
  • RMAN provides performance enhancements such as:

-Automatic parallelization of backup, restore, and recovery operations
-No generation of extra redo during online database backups
-Backups that are restricted to limit reads per file, per second to avoid interfering with OLTP work
-Prevention of flooding of any one file with reads and writes while still keeping a tape drive streaming, using multiplexing

  • RMAN has a media management API to work seamlessly with third-party media management tools interfacing with storage devices providing increased speed and reliability.
  • Under the user-managed method you need to keep track of all database files and backups. In a recovery situations you must locate backups for each datafile, copy them to the correct place using operating system commands, and choose which logs to apply. RMAN manages these tasks automatically.

Recovery Manager Components

Oracle recovery manager rman components

Oracle Recovery Manager (RMAN) components

Read more »

Oracle out of place patching reduces database downtime

To minimize downtime during patching of NON-RAC databases Out of Place Patching can be used. You can apply this approach to any Oracle patch starting from Oracle database 11g (11.2.0.2.0+) using OPatch utility. In this case time spent installing the software can be saved from the total database downtime required. However, some downtime is required for switching database services to the new Oracle database home and applying a post-upgrade script. A basic overview of the steps is below:

– Clone the existing database home online
– Apply required patch to the cloned database home using OPatch
– Switch the database services to the cloned database home
– Complete the post installation tasks for the patch applied

Notes:
– Oracle database 11g and 12c documentation describe DB_HOME cloning only in OFFLINE mode (when DB is down)
http://docs.oracle.com/cd/E11882_01/em.112/e12255/oui6_cloning.htm#OUICG298
http://docs.oracle.com/database/121/LADBI/app_cloning.htm#LADBI7853

– However, there should be no requirement to shutdown any databases, listeners, agents etc. that are running from the source home while cloning the Oracle Home directory because any processes that load the static binaries or libraries into memory should not hold a write lock.

– Oracle Out of Place patching is supported by SAP

– Out of Place patching is a recommended patching method that is used in out of the box deployment procedure of Oracle Enterprise Manager (OEM) Cloud Control 12c+ version

Oracle 12c database Out of Place patching reduce downtime

Oracle database Out of Place patching

Below we will use a combination of Oracle documentation, a few MOS Notes and a little bit of experience to manually conduct Out of Place patching of Oracle database 12c
Read more »

Oracle patch prerequisite check OPatch OEM MOS

Oracle database patching is one of the most frequently executed maintenance activities that every DBA does in his life. The task is fairly simple and straight forward using the patch instructions from My Oracle Support (MOS). However in this article I’d like to highlight the importance of different Patch Prerequisite Checks that you have to perform before doing the patching itself. I think the entire success of patching exercise depends mostly on this step as seen on the below table that represents major PSU patching steps and approximate time lines. The rest of this draft document describes some best practices, tips and code examples for doing patch prerequisite checks using OEM Cloud Control, MOS and OPatch utility. Comments, adjustments, other tips and ideas are welcome and will be included in this post.

Oracle DB PSU patching steps

Oracle database PSU patching steps

Read more »

German Oracle User Group (DOAG) Conference 2015

Kirill Loifman is DOAG 2015 conference speaker dadbm.comThe 28th edition of DOAG 2015 annual Conference + Exhibition was held November 17 – 20, 2015 in Nuremberg Conference Center. Participants had the opportunity to attend the exibition and daily lecture programs with more than 500 talks and international top speakers, plus a wide choice of workshops,  and community activities.
Interseting key notes including one with Andrew Mendelsohn, Executive Senior Vice President at Oracle, who shared the information about new developments in Oracle database 12c.
This was a great opportunity for everyone to expand the knowledge and benefit from the know-how of the Oracle community.

Thanks for all the organizers and participants.

I was speaking there also with a database related topic called:

Reduce planned database down time with Oracle technology smart

Official Abstract of my DOAG presentation:
How to design an Oracle database system to minimize planned interruptions? That depends on the requirements, goals, SLAs etc. The presentation will follow top-down approach. First we will describe major types of planned maintenance, prioritize those and then based on the system availability requirements find the best cost-effective technics to address those. A bit of planning, strategy and of course modern OS and database technics including latest Oracle 12c features will follow.


Timelines and location: Thursday, 2015-11-19, room Shanghai

The presentation consists of 3 major parts including Linux and SQL code examples:

– System downtimes and high availability basics
– Reducing planned downtime approach and methodology
– Technical part: system configurations, technics, new Oracle 12c features

See the slightly adjusted presentation material below:
– Presentation: Reduce planned database down time with Oracle technology
– Scripts: will follow

Please share your ideas, expririence or ask questions in the Comments to this post below.

You can also review my previouse DOAG 2014 presentation including live demo: Live adventure – From my PC to Oracle remote database

Some a few photos below… Read more »

Oracle database client silent installation without response file

I’m often asked questions on Oracle database or client software installation in Silent Mode with using response file. I used to do it in the past but not anymore. The silent software installation with Oracle response file is still available but I found another handy option in Oracle 11g/12c of doing the same. The same silent installation can be done directly from the command prompt without using an Oracle response file but it requires a minimum set of variables (from the response file) as arguments to the Oracle Universal Installer (OUI) (i.e “runInstaller or setup.exe”).

I give a few tested examples below to install Oracle software in Silent mode without a response file:

Oracle Database 11.2 on Linux silent installation (Enterprise Edition Software Only)

cd /opt/oracle/stage/database
./runInstaller -silent -debug -force \ Read more »

« Previous PageNext Page »

DBMS Blog Updates : Subscribe RSS RSS: Subscribe to Articles · Subscribe to Comments Subscribe RSS Receive site updates via email