Online recovery of user tables using flashback table
First Claim
Patent Images
1. A method for online recovery for a database system using an undo record comprising:
- receiving a flashback request;
generating a flashback operation for a database associated with the undo record, wherein changes introduced to the database by each transaction are stored in the undo record associated with the transaction and a database object in the database;
identifying the object in the database that was changed since the flashback time by scanning for metadata associated with the object, wherein the metadata tracks the changes and is not a portion of the transaction log; and
restoring the database object to a state as of a flashback time by reversing the changes introduced into the database object after the flashback time specified in the flashback request without taking the database system offline.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for updating databases are disclosed. In response to a flashback request, a database object is restored to a state as of a specified flashback time. The changes introduced into the database object are reversed in a sequence starting with a change introduced into the database object immediately before issuance of the flashback request and ending with a change introduced into the database object immediately after the specified flashback time.
-
Citations
35 Claims
-
1. A method for online recovery for a database system using an undo record comprising:
-
receiving a flashback request; generating a flashback operation for a database associated with the undo record, wherein changes introduced to the database by each transaction are stored in the undo record associated with the transaction and a database object in the database; identifying the object in the database that was changed since the flashback time by scanning for metadata associated with the object, wherein the metadata tracks the changes and is not a portion of the transaction log; and restoring the database object to a state as of a flashback time by reversing the changes introduced into the database object after the flashback time specified in the flashback request without taking the database system offline. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25)
-
-
22. An apparatus for online recovery for a database system using an undo record comprising:
-
means for generating a flashback operation for a database associated with the undo record, wherein changes introduced to the database by each transaction are stored in the undo record associated with the transaction and a database object in the database in response to a flashback request; means for identifying the object in the database that was changed since the flashback time by scanning for metadata associated with the object, wherein the metadata tracks the changes and is not a portion of the transaction log; and means for restoring the database object to a state as of a flashback time by reversing the changes introduced into the database object after the flashback time specified in the flashback request without taking the database system offline. - View Dependent Claims (30, 31)
-
-
26. The apparatus for online recovery for a processing system having a database system using an undo record comprising:
-
flashback module of the processing system for a database associated with the undo record to restore a database object in the database to a state as of a specified flashback time in response to a flashback request by identifying blocks of the database object that were changed since the flashback time by scanning for metadata associated with the object, wherein the metadata tracks the changes and is not a portion of the transaction log; identifying transactions that changed the blocks;
identifying undo records and restoring the database object in the database to a state as of the flashback time utilizing the undo records without taking the database system offline,wherein changes introduced to the database by the transactions are stored in the undo records associated with the transactions and the database object. - View Dependent Claims (27, 28, 29)
-
-
32. An article of manufacture for online recovery for a database system using an undo record comprising:
-
a computer-readable memory or storage medium having stored therein instructions which, when executed by a processor, cause a processing system to perform a method comprising; generating a flashback operation for a database associated with the undo record, wherein changes introduced to the database by each transaction are stored in the undo record associated with the transaction and a database object in the database in response to a flashback request; identifying the object in the database that was changed since the flashback time by scanning for metadata associated with the object, wherein the metadata tracks the changes and is not a portion of the transaction log; and restoring the database object in the database to a state as of a specified flashback time by reversing the changes introduced into the database object after a flashback time specified in the flashback request without taking the database system offline. - View Dependent Claims (33, 34, 35)
-
Specification