Technology Questions

Cursors help you manipulate the information retrieved by select statements. This can be done by assigning a name to the cursor.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

Types of Cursors:

Implicit cursors- These cursors are not declared by the programmer. They are issued when the SQL statement is executed. The open, close and fetching is done by itself.

Example:

UPDATE employee SET salary = salary * 2.1;

Here, an implicit cursor is issued to identify the set of rows in the table which would be affected by the update.

Explicit cursors- These cursors are defined by programmer. They are used in queries that return multiple rows.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

Pseudo elements allow the use of the part of element and not the element itself. They are applied to block level element, which is used for the complete block for which the CSS is being written. This allow the subpart of an element to be styled like paragraphs and headings. For example:

selector:pseudo-element {property:value;}

p: first-line {text-transform: lowercase;}

It adds the style to the first line of the code in the paragraph.

When an exception is thrown , the catch block of the try statement are examined in the order in which they appear. The first catch block that is capable of handling the exception is executed. The remaining catch blocks are ignored

When creating a thread by extending the Thread class, it is not mandatory to override the run method (If we are not overriding the run method , it is useless), because Thread class have already given a default implementation for run method. But if we are implementing Runnable , it is mandatory to override the run method. The preferred way to create a thread is by implementing Runnable interface, because it give loose coupling.

- A web worker is a JavaScript which runs in the background. It exists in external files. 

 - It is independent of other scripts and does not affect the performance of the page. 

 - Web workers are usually used for CPU intensive tasks.

Service oriented architecture (SOA) is an architectural style that supports service oriented methodology that is being added in the cloud architecture as a mandatory component. Cloud architecture support the use of on-demand access to resources and it provides lots of other facilities that are being found in SOA as well. SOA makes these requirements optional to use. But, to get the full functionality and more performance based efficiency there is a requirement for the mixture of SOA and cloud architecture.

- The principle of least privilege is used to provide more security to the computer programs. 

- The principle allows the designing of the program such that any unauthorized access is not allowed and only the person who owns the program will be able to access it. 

- The services provided should be able to access only those products that need the services. 

- Web servers that are involved in responding the queries of the web users provide only accessing to the HTML files that will serve the purpose of the programs. 

- Computer programs should be made such that it provides secure features of logging into the program with proper authentication.

- The infinite file error can be solved when the data will be read continuously from the file. 

- The error can be solved by using the keys that provide only the resources that are required. 

- The following program is as follows:

osw.write ("HTTP/1.0 200 OK\n\n"); 

while (c != -1) { 

sb.append((char)c); 

c = fr.read(); 

} 

osw.write (sb.toString()); 

- This converts the requested file in such a way that if the file exists it shows the messages as ok otherwise it shows an error.

- Limited file access is to be given to the file to remove the error from the infinite file type.