Introduction to Oracle database performance

We all know that when the Oracle database fails, we need to restore all the files in the database. During restoration, We need to redo the data to update the backup, and roll back the database to the consistent state without errors before the transaction is committed.

Oracle database backup and recovery

Users can pay attention to several common Oracle backup problems. First, backing up an Oracle database includes not only physical data backup (copies of database files ), it also includes Logical Data Backup-data export using SQL commands and submitted and uncommitted CHANGES IN THE redo log file cache.

When the Oracle database fails, relevant database files need to be restored. The Restoration Operation must use the redo data to update the backup to a new time point, and roll back the database to a consistent state without errors before the transaction is committed. If the database or IT system administrator has used the database snapshot, you may only need to use the snapshot to restore the data of the application.

In Oracle Database Backup, many files need to be backed up. They are data files, control files, online redo log files, and archived redo log files. Oracle databases are organized into one or more physical files, which are logically called tablespaces. Data files are divided into data blocks. The control file contains the database name, creation timestamp, data file, redo log file, and a Check Point and backup metadata. Redo log files record all changes to the database.

Each database has a mechanism to roll back and undo changes to curb and eliminate changes. In Oracle, this is called automatic management revocation. Withdrawing records helps roll back transaction operations, recovery, and data read consistency.

Oracle Database Backup Method

Oracle provides many methods to back up databases. These include the recovery Manager (RMAN), which can automate backup and recovery operations; Oracle data pump, which is used for logical backup of databases; and user management. User Management allows users to manually back up databases through operating system commands.

There are also a variety of other database backup and recovery software that enhances Oracle's backup utilities, such as CommVault's Simpana and IBM's Tivoli Storage Manager.

Matthew Staver, the manager of the Information Technology Department at Pentel Inc. in atosans, California, uses a series of tools. Staver said, "When we handle some special transactions, we will use the HP (Hewlett-Packard's) Storage Service EVA commercial copy software for snapshot processing, if we need to release a new database patch to Oracle, we will first create a snapshot so that we can roll back in case of any errors."

Staver has an HP Enterprise Virtual Array and a variety of HP Blade System servers to deploy and manage Oracle databases. Oracle RMAN is used for routine database backup operations. Staver also relies on HP's replication solution Management Service to clone his database for testing and development.

"When we want to refresh the Oracle instance we use for testing and development, we will take a snapshot of the product database," Staver said, "This is what we can do when the database runs together with a script called the replication solution manager by Hewlett-Packard.

[This] enables your scripts to be related to the storage Region network, enables your database to enter the hot backup mode, and places snapshots Based on Time points on SAN's VMware Host, then run the Rapid Cloning script of the Oracle database to back up all data within one or two minutes, "Staver said. For the rapid cloning process of Oracle, it takes several hours for the database administrator to launch the database. This process usually takes one or two days to restore and apply the tape.

Oracle Automatic Storage Manager

Another IT manager from Southeast University, who does not want to reveal his identity, also uses an Oracle tool to back up databases.

"We Are Using Automatic Storage Management in the Oracle cluster environment, because this allows us to create two copies of data simultaneously on the visible cluster installed in Oracle," he said, "We can back up data from the data center to the least busy node. It takes A lot of time to back up data to node. In this way, because we have crossed this time, we can back up another node B, which will shorten our backup time from about 12 hours to less than 2 hours ."

Oracle backup prompt

The following are some useful Oracle database backup best practices from experts, including:

1. When the database is in a running hot backup state, no active transactions are backed up;

2. Use Oracle tools or other third-party software to compress Oracle backup data, such as the Data Storage Manager of IBM/Tivoli. For example, with Oracle RAMN, compression of database tables can reduce the full scanning time of large tables by half.

3. If it is more important to maintain the Oracle database storage space than to back up and restore the database, you can use binary compression.