LINQ versus SqlDataReader versus DataSet performance

There is the potential that switching to DataSets rather than business objects will add a significant overhead and adversely affect performance.

• "accessing data through the DataReader is a magnitude of 27-56 times faster than accessing data using the DataSet"
  http://www.devx.com/vb2themax/Article/19887/1954?pf=true

• -------------------------------------------------------------------
  Strongly Typed DataSet Breakdown
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  175.11% slower than SQL Data Reader
  216.26% faster than LINQ to SQL
  112.17% slower than LINQ to SQL Compiled
  -------------------------------------------------------------------
  

  Performance benchmarks for LINQ vs. SqlDataReader, DataSet - LINQ Compiled Queries: Part 2 http://www.devtoolshed.com/node/12

LINQ to SQL and LINQ to Entities

The blog entry Microsoft’s Data Access Strategy has some good points on when you would consider using LINQ to Entities versus LINQ to SQL.

Object-relational impedance mismatch

Recently I found myself discussing how to an application accesses data in a database. This Wikipedia article has some good arguments for an Object-relational mapping approach. http://en.wikipedia.org/wiki/Object-Relational_impedance_mismatch