A connection pool is a mechanism to reuse connections created. Connection pooling can increase performance dramatically by reusing connections rather than creating a new physical connection each time a connection is requested..


The few advantages of data source are :

An application does not need to hardcode driver information, as it does with the DriverManager.
The DataDource implementations can easily change the properties of data sources. For example: There is no need to modify the application code when making changes to the database details.
The DataSource facility allows developers to implement a DataSource class to take advantage of features like connection pooling and distributed transactions.


A DataSource object is the representation of a data source in the Java programming language. In basic terms,

A DataSource is a facility for storing data.
DataSource can be referenced by JNDI.
Data Source may point to RDBMS, file System , any DBMS etc..


The BatchUpdates feature allows us to group SQL statements together and send to database server in one single trip.


There are two types of RowSet are there. They are:

Connected - A connected RowSet object connects to the database once and remains connected until the application terminates.
Disconnected - A disconnected RowSet object connects to the database, executes a query to retrieve the data from the database and then closes the connection. A program may change the data in a disconnected RowSet while it is disconnected. Modified data can be updated in the database after a disconnected RowSet reestablishes the connection with the database.

What is rowset? 08/27/2008

A RowSet is an object that encapsulates a set of rows from either Java Database Connectivity (JDBC) result sets or tabular data sources like a file or spreadsheet. RowSets support component-based development models like JavaBeans, with a standard set of properties and an event notification mechanism.


The values are defined in the class java.sql.Connection and are:

TYPE_FORWARD_ONLY specifies that a resultset is not scrollable, that is, rows within it can be advanced only in the forward direction.
TYPE_SCROLL_INSENSITIVE specifies that a resultset is scrollable in either direction but is insensitive to changes committed by other transactions or other statements in the same transaction.
TYPE_SCROLL_SENSITIVE specifies that a resultset is scrollable in either direction and is affected by changes committed by other transactions or statements within the same transaction.
Note: A TYPE_FORWARD_ONLY resultset is always insensitive.


The ResultSet represents set of rows retrieved due to query execution.

ResultSet rs = stmt.executeQuery(sqlQuery);


The values are defined in the class java.sql.Connection and are:

Any given database may not support all of these levels.


Type I driver is handy for prototyping
Type III driver adds security, caching, and connection control
Type III and Type IV drivers need no pre-installation
Note: Preferred by 9 out of 10 Java developers: Type IV. Click here to learn more about JDBC drivers.