How can you retrieve data from the ResultSet using JDBC? | Java JDBC

First JDBC returns results in a ResultSet object, so we need to declare an instance of the class ResultSet to hold our results. The following code demonstrates declaring the ResultSet object rs.

E.g.
ResultSet rs = stmt.executeQuery(”SELECT COF_NAME, PRICE FROM COFFEES”);


Second:
String s = rs.getString(”COF_NAME”);

The method getString is invoked on the ResultSet object rs , so getString will retrieve (get) the value stored in the column COF_NAME in the current row of rs

How can you create JDBC statements? | Java JDBC

A Statement object is what sends your SQL statement to the DBMS. You simply create a Statement object and then execute it, supplying the appropriate execute method with the SQL statement you want to send. For a SELECT statement, the method to use is executeQuery. For statements that create or modify tables, the method to use is executeUpdate. E.g. It takes an instance of an active connection to create a Statement object. In the following example, we use our Connection object con to create the Statement object statement.

How can you make the connection using JDBC? | Java JDBC

In establishing a connection is to have the appropriate driver connect to the DBMS. The following line of code illustrates the general idea:
E.g.
String url = “jdbc:odbc:Fred”;
Connection con = DriverManager.getConnection(url, “Fernanda”, “J8”); 

What Class.forName will do while loading drivers of JDBC? | Java JDBC

It is used to create an instance of a driver and register it with the DriverManager. When you have loaded a driver, it is available for making a connection with a DBMS.

What is the advantage of denormalization? | Java JDBC

Data denormalization is reverse procedure, carried out purely for reasons of improving performance. It maybe efficient for a high-throughput system to replicate data for certain data.

Is the JDBC-ODBC Bridge multi-threaded? | Java JDBC

No. The JDBC-ODBC Bridge does not support multi-threading. The JDBC-ODBC Bridge uses synchronized methods to serialize all of the calls that it makes to ODBC. Multi-threaded Java programs may use the Bridge, but they won't get the advantages of multi-threading.

What is cold backup, hot backup, warm backup recovery? | Java JDBC

Cold backup means all these files must be backed up at the same time, before the database is restarted. Hot backup (official name is 'online backup' ) is a backup taken of each tablespace while the database is running and is being accessed by the users