Oracle Exam 1Z0-599 Topic 4 Question 43 Discussion

Note:

* A multi data source can be thought of as a pool of data sources. Multi data sources are best used for failover or load balancing between nodes of a highly available database system, such as redundant databases or Oracle Real Application Clusters (Oracle RAC).

* (not B) A single GridLink data source provides connectivity between WebLogic Server and an Oracle Database service, which may include multiple Oracle RAC clusters

* High Availability Storage Solutions

If you have applications that need access to persistent stores that reside on remote machines after the migration of a JMS server or JTA transaction log, then you should implement one of the following highly-available storage solutions:

/ File-based stores (default or custom)---Implement a hardware solution, such as a dual-ported SCSI disk or Storage Area Network (SAN) to make a file store available from shareable disks or remote machines.

/ JDBC-accessible stores---Configure a JDBC store or JDBC TLOG store and use JDBC to access this store, which can be on yet another server. Applications can then take advantage of any high-availability or failover solutions offered by your database vendor. In addition, JDBC stores support GridLink data sources and multi data sources, which provide failover between nodes of a highly available database system, such as Oracle Real Application Clusters (Oracle RAC).