Technology Questions

STL stands for Standard Template Library. It is a library of container templates approved by the ANSI committee for inclusion in the standard C++ specification.

There are three types of lock, namely:

Shared – This type of lock permits two or more programs to read from the locked space but does not allow them to change it.

Update – This lock is more lenient. It permits the program to read and change the locked space.

Exclusive – This lock restricts all users from accessing the locked space.

Locking is a mechanism to ensure data integrity while allowing maximum concurrent access to data. It is used to implement concurrency control when multiple users access table to manipulate its data at the same time.

Advantages :

- Avoids deadlock conditions

- Avoids clashes in capturing the resources

- If the table structure is changed ( a field is added ), the program will have to be modified.

- Program might retrieve the columns which it might not use, leading on I/O over head.

- The chance of an index only scan is lost.

According to one-definition rule, C++ constructs must be identically defined in every compilation unit they are used in. 

As per ODR, two definitions contained in different source files are called to be identically defined if they token-for-token identical. The tokens should have same meaning in both source files. 

Identically defined doesn’t mean character-by-character equivalence. Two definitions can have different whitespace or comments and yet be identical.

A conversion constructor declared with the explicit keyword. The compiler does not use an explicit constructor to implement an implied conversion of types. It’s purpose is reserved explicitly for construction

LINQ is a programming model that is the composition of general-purpose standard query operators that allow you to work with data, regardless of the data source in any .NET based programming language. It is the name given to a set of technologies based on the integration of query capabilities into any .NET language.

No difference. There is a difference between obtain first and obtain next for an area sweep, but not when current on the owner in a set.