Research And Application Of High Availability Of ORACLE Database

With the great development of the enterprise in recent years, the information construction is expected to be one of the most important issues for an enterprise. With the continuous development of business, information data are increasing sharply, and some are even multiplying. The sharp increasing in information data shows more and more issues such as highly simultaneous access, high energy, and high availability. One of most critical issues is high availability since databases is the core of enterprise information system. Once the database is damaged, the whole operation won't work, which will influence the economy and credibility of the enterprise. Therefore, the high availability has attracted increasing attention.The enterprise is expected to solve the problem of how to keep the database running highly effectively in 24x365.With the demands of highly simultaneous access, high energy and high availability, Oracle products with high availability and reliability have also been brought into being, such as RAC,ASM and Data Guard. The technology of high availability keeps the data running in high usability.The deploying of product with high availability can make sure that the Oracle Database keep operating and offer service at any time. This can prolong MTBF, ensuring the database run in high efficiency and reliability. Moreover, recovery time is reduced to a minimum, in other words, to shorten the MTTR. Thus it can enable front end customers oblivious of the OFF time.The research mainly probes into and studies the theory and structure of the RAC, GRID, Data Guard and Recovery Manager(RMAN). Thereby, the construction and deploying of Oracle RAC?GRID and Data Guard is set up in the high availability structure of RAC, Data Guard, ASM and Recovery Manager(RMAN) accordingly. RAC is a database which is based on a number of plugs. Each plug operates a single case and all the plugs share the stored data. RAC can offer protection for database, enabling the high availability of database. Data Guard is consisted of main database and spare database. Spare database can be used on multiple computers, which synchronizes the main database through files transferring. Thus it enables the two databases to reach an agreement. Once the main database is damaged, Data Guard can be used to switch automatically into the spare database to protect the database. The structure may help to fulfill the high availability,high reliability and high stability of the database environment. The demand for the computer disaster recovery can also be met to some extent.