Technology Questions

There are four important files in order to make a bootable Windows XP operating system. These are Ntldr, Ntdetect, Boot.ini and Ntfs.sys

In a SQL Database, a 'correlated subquery' is a kind of sub query yet connected subquery is dependent on another query for a value that is returned. In case of execution, the sub query is executed first and afterwards the correlated query will be executed.

Optimized code tends to run faster and make more efficient use of the system’s resources. Optimized codes are also less susceptible to errors and take lesser space in memory and in file size.

- Use a COBOL II CALL statement to invoke a subprogram. This method is transparent to CICS, which sees only the one load module. 

- EXEC LINK is similar to a call; it invokes a separate CICS program and ends with a RETURN to the invoking program

- EXEC XCTL which transfers control to another CICS program and does not get control 

back. 

COBOL II allows for static calls which are more efficient than the LINK instruction which establishes a new run-unit. 

A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests. Sessions are commonly used to store temporary data to allow multiple PHP pages to offer a complete functional transaction for the same visitor.

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.

Trigger allows us to execute a batch of SQL code when an insert, update or delete command is executed against a specific table.

Triggers are special types of stored procedures that are defined to execute automatically in place of or after data modifications. They can be executed automatically on the insert, delete and update operation.

Copy() makes a copy of the file. It returns TRUE on success. It can copy from any source to destination. Move simply Moves the file to destination if the file is valid. While move can move the uploaded file from temp server location to any destination on the server. If filename is a valid upload file, but cannot be moved for some reason, no action will occur.