What is the principle behind Oracle’s flashback technology?
Oracle Flashback technology is a database recovery and querying technology that allows for database restoration to a previous time point or specific database state without the use of traditional recovery methods. The principles of Flashback technology mainly involve the following aspects:
- Flashback Log: When the flashback feature is enabled in the database, Oracle automatically creates and manages flashback logs, which contain historical state information of the database.
- Flashback Data Files: Oracle flashback technology uses flashback logs with the help of flashback data files to recover database files to a specific point in time without the need for a full recovery.
- Flashback Query is a method for querying historical data in a database by specifying a time range to see the state of an object at a specific point in the past without needing to restore the entire database.
- Flashback Transaction is a technology that allows a database to be restored to a specific point before a transaction began, which is very useful for correcting mistakes or errors.
The core principle of flashback technology is to restore a database to a specific time point or state in the past using flashback logs and data files, allowing for quick recovery and querying. This technology simplifies the recovery process, providing more reliable and flexible data recovery and querying functions.
