As we know that SYSTEM – stores the data dictionary. Being an Oracle DBA we all know the importance of SYSTEM tablespace. In these below lines, we can have actual technical knowledge about system’s information. SYSTEM – a tablespace that is always used to store SYSTEM data that includes data about tables, indexes, sequences, and other objects – this metadata […]
Articles Tagged: RECOVERY
Recover sparse corrupted data blocks one several datafiles
Being an Oracle DBA we all are known about data block. Here this line explains the technical definition of data block A data block is the smallest unit of storage in an Oracle database. Every database has a default block size (specified when the database is created), although blocks in different tablespaces may have different […]
Recover a never backed up tablespace after losing its datafile
In this post, we are going to learn steps which are use recover a never backed up tablespace after losing its datafile and even the current controlfile after the autobackup feature completes its job. This crash involves the lost of the “never backed up” tablespace and of the current controlfile. Let’s start with an example. Our […]
Retrieve the DATABASE IDENTIFIER from datafiles or online logs
This article is about the steps which require recovery when we retrieve the DATABASE IDENTIFIER dumping it from datafiles or online and archived redo logs . DBID stands for database identifier, which is a unique identifier for each Oracle database running. It is found in control files as well as datafile header. If the database is open […]
Recover from a loss of all redo log members of the CURRENT group
The most crucial and vital structure for recovery operations is the online redo log, which consists of two or more pre-allocated files that store all changes made to the database as they occur. Every instance of an Oracle database has an associated online redo log to protect the database in case of an instance failure. […]
Recover from a loss of all redo log members of an ACTIVE group
In the last post, we have learned about multiple kinds of a recovery scenario. Now in this article, we are going to learn about the steps which are used How to recover from a loss of all redo log members of an ACTIVE group. As we all know what is active group ACTIVE status means that there are […]
Recover from a loss of all redo log members of an INACTIVE group
We all know that redo log has three kinds of a group like active, inactive, current. They all have different use and as well as different meaning.Let’s simulate a loss of all redo log members of an inactive group. If you have completely lost one redo log group your database won’t be able to open. […]
Recover from a loss of one current redo log member of a multiplexed group
Today we are going to learn about the recovery from a loss of one redo log member of a multiplexed group. Being the Oracle DBA we all know the importance of change in normal life as well as database life. A single change in the database makes a huge difference. We all are well known […]
Recover from a loss of the system critical UNDO tablespace on the original location
In this phase of recovery, we are going to have a look on recover from a loss of the system critical UNDO tablespace on the original location. I hope this phase will be useful for you. As we all know that UNDO tablespace stores undo segments, generally used to explicitly (ROLLBACK command) or implicitly (a failed […]
Recover from a loss of the SYSTEM tablespace on different location
This post is about the steps used for recover as from a loss of the SYSTEM tablespace on a different location. As DBA we all are aware of system tablespace that it always contains the data dictionary tables for the entire database. In particular, this example will restore the lost tablespace to another location, just […]