LINQ interview questions

What is Language Integrated Query (LINQ)?
LINQ is a set of extensions to .NET Framework that encapsulate language integrated query, set and other transformation operations. It extends VB, C# with their language syntax for queries. It also provides class libraries which allow a developer to take advantages of these features.

Difference between LINQ and Stored Procedures.
Stored procedures normally are faster as they have a predictable execution plan. Therefore, if a stored procedure is being executed for the second time, the database gets the cached execution plan to execute the stored procedure.
LINQ supports type safety against stored procedures.
LINQ supports abstraction which allows framework to add additional improvements like multi threading. It’s much simpler and easier to add this support through LINQ instead of stored procedures.
LINQ allows for debugging using .NET debugger, which is not possible in case of stored procedures.
LINQ supports multiple databases against stored procedures which need to be re-written for different databases.
Deploying LINQ based solution is much simpler than a set of stored procedures.
Pros and cons of LINQ (Language-Integrated Query)
Pros of LINQ:

Supports type safety
Supports abstraction and hence allows developers to extend features such as multi threading.
Easier to deploy
Simpler and easier to learn
Allows for debugging through .NET debugger.
Support for multiple databases
Cons of LINQ:

LINQ needs to process the complete query, which might have a performance impact in case of complex queries
LINQ is generic, whereas stored procedures etc can take full advantage of database features.
If there has been a change, the assembly needs to be recompiled and redeployed.

Disadvantages of LINQ over stored procedures:

LINQ needs to process the complete query, which might have a performance impact in case of complex queries against stored procedures which only need serialize sproc-name and argument data over the network.
LINQ is generic, whereas stored procedures etc can take full advantage of the complete database features.
If there has been a change, the assembly needs to be recompiled and redeployed whereas stored procedures are much simpler to update.
It’s much easier to restrict access to tables in database using stored procedures and ACL’s than through LINQ.
Can I use LINQ with databases other than SQL Server? Explain how
LINQ supports Objects, XML, SQL, Datasets and entities. One can use LINQ with other databases through LINQ to Objects or LINQ to Datasets, where the objects and datasets then take care of database specific operations and LINQ only needs to deal with those objects, not the database operations directly.