Interview Questions

We need to first login to the data base as: SQLPLUS followed by user_name/password. Then we need to execute the following query:

CREATE USER user_name IDENTIFIED BY abcd; in this query a user_name suggest the user that is created which has a password abcd which is required for login in database.

It is a single computer in a network reserved for serving the needs of the network.

To create directory on the HD we use mkDir() method:

boolean mkDir();

This method returns true if the directory is created on HD

This method returns false if the directory is already existing on HD

- Web servers can be infiltrated using the command shell by an attacker to read the HTML files that is getting transferred. 

- If the set-uid scripts are not proper and bad then the infiltration can happen by the attacker. 

- The processes are not given proper permissions so that the password can be changed by using the “passwd” command to change the password of the system.

- This also authenticates the user for accessing the system and the files on it containing the data. 

- The program that is used in the operating system doesn’t follow the principle of least privilege and lead to security issues.

Call Transaction Method: In Call Transaction method we call the transaction in BDC program itself. If we want this program is executed by some one else then we need to expose the code to him. Call Transaction Method Works in Foreground. No Display Mode is equal to Background Processing in call transaction method. Call Transaction Method can handle only one Application at a time. In Call Transaction Method no Log File by Default. We have to design Log File by using BDCMSGCOLL. Call Transaction Method Updates the Database Asynchronously. (Note: Asynchronous updation is Faster than Synchronous)
 
Batch Session Method: On the other hand in batch session method we create a session which can be executed at any time by any authorized person without exposing the code of the program. Session Method works in Background and as well as in Foreground. Session Method can handle Multiple Applications at a time. Session Method holds Log File by Default. Session Method Updates the Database Synchronously.

The wait(), notify(), and notifyAll() methods are used to provide an efficient way for threads to wait for a shared resource. When a thread executes an object's wait() method, it enters the waiting state. It only enters the ready state after another thread invokes the object's notify() or notifyAll() methods..

A table of data representing a database result set, which is usually generated by executing a statement that queries the database.

ResultSet object maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set.