Skip to main content

Types of Backups in RMAN

RMAN is very flexible and it offers many different types of backups.  We need to start with a list of backup types:
·         Full backup:  A full backup backs up all data files in the database, block-by-block, a standalone backup with everything you need to recover to the point in time when the full backup was collected.

·         Level 1 backup:  A level 1 backup includes only those blocks that have been changed since the “parent” backup was taken. Remember a parent backup may be either a level 0 or a level 1 backup.

·         Level 0 backup:  A level 0 incremental backup is physically identical to a full backup and it includes every data block in the file except empty blocks. The only difference is that the level 0 backup is recorded as an incremental backup in the RMAN repository, so it can be used as the parent for a level 1 backup.
·         Incremental backup:  An incremental backup can be either level 0 or level 1.
There are two types of incremental backups, “differential” and “cumulative”.  See my full notes on incremental differential vs. incremental cumulative backups.

·         Differential Incremental Backup:  When using differential incremental backup (the default type of incremental backup), RMAN looks for changed data blocks which were changed after last level 1 incremental backup. It there’s no level 1 backup made before it, it takes a backup of the changed data blocks which were made after level 0 incremental backup. 
·         Cumulative Incremental Backup:  In a cumulative incremental backup RMAN takes backup of all changed data blocks after level 0 or level 1 incremental backup.  Like a differential backup, incremental backups also back up only the changed data blocks, but an incremental backup only backs up the data that has changed since the last backup.  If the last backup was also an incremental backup, the current incremental backups only records “changes to the changes”, a much smaller set of block changes, and hence, a much smaller recovery time than a differential backup.

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

Exp/ Imp vs. ExpDP/ ImpDP in Oracle 10g

ORACLE Export (exp) vs Datapump (expdp)    ORACLE provides two external utilities to transfer database objects from one database to another database. Traditional exports (exp /imp) are introduced before 10g. Then from 10g, ORACLE introduced datapump (expdp / impdp) as an enhancement to traditional export utility. Traditional Export (exp/ imp) This is an ORACLE database external utility, which is used to transfer database objects from one database server to another database server. It allows transferring the database objects over different platforms, different hardware and software configurations. When an export command is executed on a database, database objects are extracted with their dependency objects. That means if it extracts a table, the dependences like indexes, comments, and grants are extracted and written into an export file (binary format dump file). Following is the command to export a full database, Cmd > exp userid=username/password@exportdb_...
Post a Comment
Read more

Hi! I'm Java...

Java is a computer programming language. It enables programmers to write computer instructions using English based commands, instead of having to write in numeric codes. It’s known as a “high-level” language because it can be read and written easily by humans. Like English, Java has a set of rules that determine how the instructions are written. These rules are known as its “syntax”. Once a program has been written, the high-level instructions are translated into numeric codes that computers can understand and execute. Who Created Java? In the early nineties, Java was created by a team led by James Gosling for Sun Microsystems. It was originally designed for use on digital mobile devices, such as cell phones. However, when Java 1.0 was released to the public in 1996, its main focus had shifted to use on the Internet. It provided more interactivity with users by giving developers a way to produce animated webpages . Over the years it has evolved as a successful language for ...
1 comment
Read more

Setting up OpenGL environment for Microsoft Visual C++

Hi Friends, before starting the setting up OpenGL environment, please do the following first: 1.       Install Microsoft Visual C++ 6.0 (Comes with Ms Visual Studio 6.0) 2.       Download the file called “opengl95.exe” and “glutdlls.zip” from internet. [Just open browser-> navigate http://www.google.com -> type upper mentioned file name and search -> you will definitely find the appropriate link to download.] 3.       Run opengl95.exe file and it will be extracted and will be generated some files. Copy those files and 4.       Extract the file “glutdlls.zip” and it will also generate some more files. 5.       Now, combine all extracted files from two sources (opengl95.exe and glutdlls.zip) and place in one location. Setting up OpenGL environment for Microsoft Visual C++ With any system, you can start with a C\C++ compiler and install ...
Post a Comment
Read more