Oracle International Corporation

Other

Stephen John Vivian

George H Claborn

Raymond Guzman

Douglas Andrew Voss

Mahesh Baburao Girkar

Benedicto Elmo Garin, Jr

Steve Lee

Jiangbin Luo

Benedito Elmo Garin, Jr

Benoit Dageville

Yunrui Li

Mohamed Ziauddin

Carol L Colrain

Mark Charles Ramacher

Vinay H Srihari

Alex Tsukerman

Kevin S Neel

Jonathan Giloni

Nitin Karkhanis

Sreenath Bodagala

Michael Harvey

Robert McGuirk

Xiaoli Qi

Sean Joseph Connolly

Robert R McGulrk

Gary Allison

Michael Cusson

Techniques are described for preserving the inflight sessions failing over from a primary database to the replicated logical database of the primary database. In an implementation, prior to failover, when the primary database server receives a commit for a transaction, the process stores a commit indication that the transaction has been committed by performing a corresponding SQL command. The commit indication is replicated to the logical replica database by virtue of the replication of the SQL command and its execution on the logical replica database. Accordingly, the standby database server in the failover session may successfully request for the outcome of the transaction. Techniques are also described for the client-side LOB references to be preserved when failing over to the logical replica database, for AS OF queries preserved, and for versioning of checksums, signatures and structures across logical replicas.

Failover of database sessions to a logical replica database

A computer readable medium storing a database query language statement tuning base in a tuning base memory location is disclosed. The tuning base includes tuning information for one or more query language statements. The tuning information for each statement includes one or more tuning actions for the statement, and a signature to allow an optimizer to identify the one or more tuning actions for the statement.

SQL tuning base

Techniques used in an automatic failover configuration having a primary database system, a standby database system, and an observer for preventing divergence among the primary and standby database systems while increasing the availability of the primary database system. In the automatic failover configuration, the primary database system remains available even in the absence of both the standby and the observer as long as the standby and the observer become absent sequentially. The failover configuration further permits automatic failover only when the observer is present and the standby and the primary are synchronized and inhibits state changes during failover. The database systems and the observer have copies of failover configuration state and the techniques include techniques for propagating the most recent version of the state among the databases and the observer and techniques for using carefully-ordered writes to ensure that state changes are propagated in a fashion which prevents divergence.

Automatic failover configuration with lightweight observer

Techniques used in an automatic failover configuration having a primary database system, a standby database system, and an observer. In the automatic failover configuration, the primary database system remains available even in the absence of both the standby and the observer as long as the standby and the observer become absent sequentially. The failover configuration may use asynchronous transfer modes to transfer redo to the standby and permits automatic failover only when the observer is present and the failover will not result in data loss due to the asynchronous transfer mode beyond a specified maximum. The database systems and the observer have copies of failover configuration state and the techniques include techniques for propagating the most recent version of the state among the databases and the observer and techniques for using carefully-ordered writes to ensure that state changes are propagated in a fashion which prevents divergence.

Database system configured for automatic failover with user-limited data loss

Automatic failover configuration with redundant abservers

Database system configured for automatic failover with no data loss

A graphical user interface based method of configuring automatic failover from a primary database system to a standby database system that is coupled to the primary database system by a network. Also coupled to the network is an observer process that is independent of the database systems and that initiates the failover process. The observer periodically pings the database systems to determine whether a failover is necessary. The graphical user interface permits a user to specify the primary and secondary database systems, configure the observer, and specify conditions under which a failover may occur and to enable automatic failover. A failover context is created from the inputs to the GUI and stored in persistent storage belonging to the database systems. If the Observer's context is stale, the Observer fetches the database system's context.

System and method of configuring a database system with replicated data and automatic failover and recovery

Growing community of inventors

Londonderry, NH, United States of America

Stephen John Vivian