Technology Questions

Executing two or more blocks (threads) of a program at a time is called MultiThreading.

A call to onStop method happens when an activity is no longer visible to the user, either because another activity has taken over or if in front of that activity.

User names and passwords in PHP can be encrypted using md5 function.

MD5 function calculates the md5 hash of a string. It is basically used for encryption. It is also used for digital signature applications, where a large file must be "compressed" in a secure manner.

Example:

Md5($str);

Crypt() function can also be used to encrypt a string,. It used MD5, DES or blow fish algorithms for encryption.

Syntax:

Crypt(str, salt)

Salt is an optional parameter used to increase the number of characters encoded, to make the encoding more secure

Contextual selector addresses specific occurrence of an element.
It is a string of individual selectors separated by white space (search pattern), where only the last element in the pattern is addressed providing it matches the specified contex.

The mapreduce framework contains most of the key architecture principles of cloud computing such as:

- Scale: The framework is able to expand itself in direct proportion to the number of machines available.

- Reliable: The framework is able to compensate for a lost node and restart the task on a different node.

- Affordable: A user can start small and over time can add more hardware.

These objects provide two levels of scope:

Application State

Data stored in the application object can be shared by all the sessions of the application.

Application object stores data in the key value pair.

By default the maximum size is 2MB. and we can change the following
setup at php.iniupload_max_filesize = 2M

Windows XP supports four major file systems: FAT12, FAT16, FAT32 and NTFS. This means that Windows XP can be installed on these file systems. The use of NTFS is preferred especially when using a bigger hard drive space.