<property name="show_sql">true</property>
This tell Hibernate to log the SQL statements it is issuing.
<property name="dialect"></property>
This tells Hibernate the Dialect to use. This value will change depending on the version of Hibernate you are using. The various dialects Hibernate ships with are described in the Hibernate
JavaDocs.
<property name="connection.url"></property>
This is the
JDBC connection url Hibernate can use. The value for this is defined in the Oracle
JDBC Driver documentation.
<property name="connection.driver_class"></property>
This defines the driver class. Again, this is defined in the Oracle
JDBC Driver documentation.
<property name="connection.username"></property>
This is the username to connect to Oracle with.
<property name="connection.password"></property>
...and this is the password they use.
what is <property name="connection.datasource"></property> ?
why it is used for & is it really needed for every application....
This is the JNDI name of a DataSource to use. It would be used in preference to the above properties.