Technology Questions

Oracle Real Application Clusters (RAC) is a software component we can add to a high-availability solution that enables users on multiple machines to access a single database with increased performance. RAC comprises two or more Oracle database instances running on two or more clustered machines and accessing a shared storage device via cluster technology. To support this architecture, the machines that host the database instances are linked by a high-speed interconnect to form the cluster. Oracle RAC offers features in the following areas:

- Scalability

- Availability

- Load balancing

- Failover

Structure: Initially (in C) a structure was used to bundle different type of data types together to perform a particular functionality. But C++ extended the structure to contain functions also. The major difference is that all declarations inside a structure are by default public.
Class: Class is a successor of Structure. By default all the members inside the class are private.

This problem isn't too hard. You just need to start at the head of the list, and iterate to the end. At each node, swap the values of pNext and pPrev. Finally, set pHead to the last node in the list.

Node * pCurrent = pHead, *pTemp;

while (pCurrent)

{

  pTemp = pCurrent->pNext;

  pCurrent->pNext = pCurrent->pPrev;

  pCurrent->pPrev = temp;  

  pHead = pCurrent;

  pCurrent = temp;

}

The mail() function of PHP is quite robust for sending bulk emails. A SMTP server can also be directly used from the script. PHPmailer class can be used for sending emails.

Advantages of 3G:

- Overcrowding is relieved in existing systems with radio spectrum
- Bandwidth, security and reliability are more
- Provides interoperability among service providers
- Availability of fixed and variable rates
- Support to devices with backward compatibility with existing networks
- Always online devices – 3G uses IP connectivity which is packet based
- Rich multi media services are available

Disadvantages of 3G:

- The cost of cellular infrastructure , upgrading base stations is very high
- Needs different handsets.
- Roaming and data/voice work together has not yet been implemented
- Power consumption is high
- Requires closer base stations and are expensive
- Spectrum-license costs, network deployment costs and handset subsidies subscribers are tremendous.

TDM is a digital process that can be applied when the data rate capacity of the transmission  medium is greater than the data rate required by the sending and receiving devices.

- Positioning: Is some what where we need the object to be placed in the graphical view i:e on screen. If we talk in DHTML sense then we have two types of positioning: Relative and Absolute.

Relative Positioning: Relative positioning is the same as the current HTML3 layout and is best reserved for situations where you want to be sure that the content will revert to this default inside a document that also uses absolute positioning.

Absolute Positioning: In DHTML absolute positioning means that the object will remain at the same position regardless of the condition of other elements and the size of the browser. In simple languages if an object/image is absolutely positioned (STYLE="position: absolute;"), with an offset of 150 pixels to the right and 250 pixels down from the left-hand corner of the browser screen then it will avail this position what ever the circumstances may be.

- Style Modifications: Style modification indicates the changes in the presentation or the view part that are being made in web page. This part comes under Cascading Style Sheet where the user style his web page by using the attributes and the tags that are pre-defined in CSS.

- Event Handling: As explained earlier Events is the beating heart of any JavaScript application. For handling event in DHTML we attach event handler to HTML elements. The event handler waits until a certain event, for instance a click on a link, takes place. When it happens it handles the event by executing some JavaScript code that has been defined by us. After it has executed the code the event handler comes to its initial state and waits for the user to fire any event. Hence to handle events in DHTML we need to register an event handler.

• Mac OS 


• Windows Vista 


• Windows XP SP2 


• Windows 2000 


• Windows Server 2003 


• Linux (Moonlight)