The Dataset is an core of disconnected architecture.Disconnected architecture means once you have retriveed the data from the database the connect of the datasource is dropped.The disconnected data become very commonlyThe dataset for the disconnected data from the Dataset object.The DataReader is an readonly ,forward only stream from the database.While using the datareader can improve the application performance reduce the system overhead because only one buffer row at a time in memory.
The following are the major differences between "DataSet" and "DataReader" 1. "DataSet" is a disconnected architecture, while "DataReader" has live connection while reading data. If we want to cache data and pass to a different tier "DataSet" forms the best choice and it has decent XML support. Data can manipulate in the "DataSet" 2. When application needs to access data from more than one table "DataSet" forms the best choice. 3. Whereas, "DataReader" is connection oriented, readonly and forward only. 4. The biggest drawback of DataSet is spped. As "DataSet" carry considerable overhead because of relations, multiple tables etc speed is slower than "DataReader". Always try to use "DataReader" wherever possible, as it's meant specially for speed performance. More Questions & Answers are available at: http://interview-questionsandanswers.blogspot.com/