Abstract: A clustered database environment includes multiple database instances that appear as one server. An application server can use a data source and connection pools to connect with the clustered database. A notification service broadcasts notifications describing state changes in the database instances, which are then used by the data source and connection pools to control access to the database instances. A data source configuration allows for specification of a preferred affinity policy. A session affinity policy is used to provide database instance affinity for database access made under the context of a web session, whereby database operations are directed to a particular instance for a period of time when the application may be performing multiple, related updates to a specific data set. Directing such operations to a single database instance can be used to improve application performance due to increased local cache utilization.

Abstract: A primary task manager, which is a local task manager, can perform a distributed task on a local server. If the performing of the task with the local task manager succeeds, the distributed task can then be propagated to at least one secondary task manager, which is a remote task manager. The remote task manager is capable of performing the distributed task. If the performing of the task with the local task manager fails, an undo task that is associated with the distributed task can be performed.

Abstract: First data that represents a level associated with an element within an expression, such as an XPath expression, is generated from the expression, and stored in one or more columns of a table. Second data that represents a condition on an attribute of the element is generated from the expression, and stored in one or more columns of the same or a different table. A plurality of expressions can be processed as such, and a determination made whether any of the expressions match with a given hierarchical data item, such as an XML document, that includes a value that corresponds to an attribute that is associated with an element that resides at a particular level within the data item. Such determination is made based on whether the particular level matches the first data and the value satisfies the second data associated with a given expression.