Your server includes an application that uses a generic JDBC data source to connect to a
database. However, the network connection between the server and the database is not 100%
reliable.
You wish to avoid scenarios in which the application fails due to a failed JDBC connection. Identify
two data source attributes to help accomplish this.
A.
Statement Cache
B.
Pool Reserve Mode
C.
Test Table Name
D.
Test Connection Mode
E.
Test Connections on Reserve
Explanation:
A: Each connection in a data source has its own individual cache of prepared and
callable statements used on the connection. However, you configure statement cache options per
data source. That is, the statement cache for each connection in a data source uses the statement
cache options specified for the data source, but each connection caches it’s own statements.
E: When Test Connections On Reserve is enabled, when your application requests a connection
from the data source, WebLogic Server tests the connection using the query specified in Test
Table Name before giving the connection to the application.
Testing reserved connections can cause a delay in satisfying connection requests, but it makes
sure that the connection is viable when the application gets the connection.
Reference: Oracle Fusion Middleware Oracle WebLogic Server Administration Console Online
Help 11g Release 1, Configuring JDBC Data Sources
http://docs.oracle.com/cd/E12839_01/web.1111/e13737/jdbc_datasources.htm#i1192665
“C” and “E” is correct answer
To improve performance, WebLogic Server can cache prepared and callable statements used in your applications (enabled by default). When an application or EJB calls any of the statements stored in the cache, WebLogic Server reuses the statement stored in the cache. Caching is used to improve the performance, not to avoid failure scenarios, right? So how A can be right?
When you use a prepared statement or callable statement in an application or EJB, there is considerable processing overhead for the communication between the application server and the database server and on the database server itself. To minimize the processing costs, WebLogic Server can cache prepared and callable statements used in your applications. When an application or EJB calls any of the statements stored in the cache, WebLogic Server reuses the statement stored in the cache. Reusing prepared and callable statements reduces CPU usage on the database server, improving performance for the current statement and leaving CPU cycles for other tasks.
Reference:
https://docs.oracle.com/cd/E11035_01/wls100/jdbc_admin/jdbc_datasources.html#statementcache
So Statement Cache is used for reducing CPU cost and improve the performance not avoid the failure between the application and the database. A is wrong !
C,E
C & E