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Applied Oracle Security: Developing Secure Database and Middleware Environments- P54

Applied Oracle Security: Developing Secure Database and Middleware Environments- P54:Computer security is a field of study that continues to undergo significant changes at an extremely fast pace. As a result of research combined with increases in computing capacity, computer security has reached what many consider to be “early adulthood.” From advances in encryption and encryption devices to identity management and enterprise auditing, the computer security field is as vast and complex as it is sophisticated and powerful | 504 Part IV Applied Security for Oracle APEX and Oracle Business Intelligence logical SQL to see what can be satisfied via cache. Oracle BI uses a shared cache mechanism to increase performance. The security implications of this cache are discussed in detail in Chapter 14. If the cache cannot be used to satisfy the request the BI server will use the metadata defined in the RPD to construct a physical SQL statement in the case of a relational database source to be issued to the underlying data sources. NOTE Oracle BI does support a variety of data sources including XML relational databases and several multidimensional databases. It also supports multiple data sources in a single request. For simplicity the examples provided with this book will often refer to data sources as the database even though it could be much more than just a database. Connection Pools As mentioned the BI server can be used to query a variety of backend data sources. To set up communication between the BI server and these data sources you use connection pools in the Administration tool. The name connection pools can sometimes be misleading. Sometimes these connections really act like connection pools a cache of database connections. At other times these connection pools represent a location of data. To help you understand this let s look at several examples. Connection Pools by Data Source Type Connection pools are set up for different types of data sources. Consider for example relational databases. The first thing you need to do is decide on a call interface. For Oracle databases you should always use Oracle Call Interface OCI . Next you decide on the maximum number of connections that this pool should allow. The BI server uses the connection pools in the order in which they are listed in the Administration tool. When you attempt to query a data source the BI server will use the first connection pool that you have permission to access and that has an open connection available. As shown in .