gistfile1.cs

XmlMetadataSource source = XmlMetadataSource.FromAssemblyResource("Northwind.rlinq"); 
var model = source.GetModel(); 

var productType = model.PersistentTypes.FirstOrDefault(x => x.Name == "Product"); 
productType.OptimisticConcurrencyControlStrategy = OptimisticConcurrencyControlStrategy.Timestamp; 

//Making sure there is no cached database. 
Database.Get("NorthwindEntityDiagrams", new BackendConfiguration() { Backend = "mssql" }, model).Dispose(); 

//initialize the database with the modified metadata  
Database.Get("NorthwindEntityDiagrams", new BackendConfiguration() { Backend = "mssql" }, model); 

//Now create a normal context, because there already is a cached database instance with the modified metadata, one would not be created.;  
using (NorthwindEntityDiagrams context = new NorthwindEntityDiagrams()) 
{ 
	Console.WriteLine(context.Categories.First().CategoryName); 
} 
  
//Disposing the database object so that the next call uses the correct metadata. 
Database.Get("NorthwindEntityDiagrams", new BackendConfiguration() { Backend = "mssql" }, model).Dispose();