1. A system for supporting session affinity in a data source and clustered database environment, comprising: a clustered database system, and a notification service associated with a plurality of database instances therein, wherein the notification service is used to broadcast notifications that describe state changes in the clustered database; an application server, and a data source and connection pools associated therewith, wherein the data source and connection pools are used to manage connections to the plurality of database instances in the clustered database, and wherein the data source can use session or session-based affinity, wherein database operations are directed to a particular database instance for a period of time when the application may be performing multiple, related updates to a specific data set.