Performing Incomplete Recovery Incomplete recovery may sometimes be necessary. For example, there may be a desire to send the database back in time due to error, incorrect DML changes, or sometimes incomplete recovery may be the only option (due to missing archivelog sequence). Incomplete recovery recovers the database to a point in time in the past. There are three ways to perform incomplete recovery: change-based recovery, cancel-based recovery, and time-based recovery. This article … [Read more...] about Oracle Database : Performing Incomplete Recovery from a missing archivelog file (Change-Based, Cancel-Based, Time-Based)
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Beginners Guide to Automatic Storage Management (ASM)
The Basics Automatic Storage Management (ASM) provides vertical integration of the file system and the volume manager for Oracle database files. ASM can provide management for single symmetric multiprocessing (SMP) machines or across multiple nodes of a cluster for Oracle Real Application Clusters (RAC) support. Oracle ASM Cluster File System (ACFS) is a multi-platform, scalable file system, and storage management technology that extends ASM functionality to support application files outside … [Read more...] about Beginners Guide to Automatic Storage Management (ASM)
How to upgrade RMAN catalog SCHEMA from 11g to 12.1.0.2 without upgrading the catalog database
Question: Our rman catalog database is 11.2.0.3 right now, do I need to upgrade the database to 12.1.0.2 first, and then upgrade the catalog to 12.1.0.2? The version of the RMAN catalog database does not need to match that of the recovery catalog. Therefore you can upgrade the RMAN catalog without upgrading the RMAN database. This is true of any version of the database, not only 12c. If you are intending to upgrade the catalog schema to 12c then you need to run these 2 … [Read more...] about How to upgrade RMAN catalog SCHEMA from 11g to 12.1.0.2 without upgrading the catalog database
How an SQL query is executed in Oracle Database
The following example describes Oracle database operations at the most basic level. It illustrates an Oracle database configuration in which the user and associated server process are on separate computers, connected through a network. 1. An instance has started on a node where Oracle Database is installed, often called the host or database server. 2. A user starts an application spawning a user process. The application attempts to establish a connection to the server. (The connection … [Read more...] about How an SQL query is executed in Oracle Database
RMAN Pluggable Database Backup and Recovery in a Multitenant Environment
What is a Container Database? A 12c database is either a non-Container Database or a Container Database - from here on referred to as non-CDB or CDB respectively. All databases created prior to 12c are non-CDBs. A CDB is an Oracle database that includes zero, one, or many customer-created Containers or Pluggable Databases referred to as PDB. The CDB has: one ROOT container (CDB$ROOT) containing SYSTEM, SYSAUX, UNDO, and TEMP tablespaces, Controlfiles and Redologs one SEED container … [Read more...] about RMAN Pluggable Database Backup and Recovery in a Multitenant Environment
How To Setup UDEV Rules For RAC OCR And Voting Devices on Partitions
The Goal How to setup UDEV rules RAC OCR and Voting Devices on different partitions, rather than a raw disk. Let's assume that the disk is sdb, which have 3 partitions: sbd1 sbd2 sdb3 It also applies to partitions over different hard disk. The Solution 1. Find the WWID of the disk: # /sbin/scsi_id -g -u -s /block/sdb SATA_VBOX_HARDDISK_VBbb8af1a8-4d4db09b_ Here we got an WWID of 'SATA_VBOX_HARDDISK_VBbb8af1a8-4d4db09b_'. 2. Create an custom UDEV rule: Create a new rule under … [Read more...] about How To Setup UDEV Rules For RAC OCR And Voting Devices on Partitions
Oracle Database Basics – User Accounts
To access the database, a user must specify a valid database user account and successfully authenticate as required by that user account. Each database user has a unique database account. Oracle recommends this to avoid potential security holes and provide meaningful data for certain audit activities. However, users may sometimes share a common database account. In these rare cases, the operating system and applications must provide adequate security for the database. Each user account … [Read more...] about Oracle Database Basics – User Accounts
Oracle Database Storage Architecture – Overview
The files that comprise an Oracle database are as follows: Control files: Each database has one unique control file that contains data about the database itself (that is, physical database structure information). Multiple copies may be maintained to protect against total loss. It can also contain metadata related to backups. The control file is critical to the database. Without the control file, the database cannot be mounted or opened. Data files: Contain the user or application data of … [Read more...] about Oracle Database Storage Architecture – Overview
Oracle RMAN Pluggable Database Point in Time Recovery
Point in time recovery of a Pluggable Database (from hereon referred to as a PDB) requires ALL files including UNDO to be restored and recovered to the specified time. As all PDBs write to the ROOT UNDO tablespace, point in time recovery of a PDB will use an auxiliary instance and will restore the CDB$ROOT UNDO, SYSTEM, SYSAUX, and SYSEXT tablespaces into the ROOT of the auxiliary instance. The datafiles of the PDB itself are restored and recovered in-situ. The auxiliary database is created … [Read more...] about Oracle RMAN Pluggable Database Point in Time Recovery
Oracle RMAN 12c – New Features
This post provides information on enhancements available in RMAN within Oracle 12c. Support for Container and Pluggable Databases RMAN in 12c provides full backup and recovery support for a Pluggable Database environment. You can perform the backup of the entire container database (CDB), either full or using an incremental backup strategy, or one/many pluggable databases (PDB). SYSBACKUP Privilege In 12c, Oracle support for separation of database administration (DBA) duties by … [Read more...] about Oracle RMAN 12c – New Features