Using both Enterprise library and Entity framework as DAL for same application

Question

We have been using EF for large amount of data  retrieval in our current application. We faced performance related issues with using EF with large data retrieval and manipulation.
We need to extend the same project with some additional functionality similar to what currently exists in the application and uses EF.
For the new functionality, we do not want to use EF and want to use enterprise library for Data access.
My question is if we use both entity framework for parts of the application data access mechanism and enterprise library for other parts of application data access, are there any known issues?
if there are any best practices to be followed please share .

Answer 1

We have been using EF for large dataset retrieval in our current application. We faced performance related issues with using EF for large data set's  .
Dataset? What are you talking about?  If you are using the salad bowl, the dataset with datatables, then here is the reason not to use them.
http://lauteikkehn.blogspot.com/2012/03/datatable-vs-list.html
My question is if we use both entity framework for parts of the application data access mechanism and enterprise library for other parts of application data access, are there any known issues?
What is Entlib going to buy you in performance? It's going to buy you nothing. You'll be better of going to the EF backdoor, use SQL command objects, inline T-SQL, sprocs, datareder and using custom objects or objects off of the virtual model returning a
single object or objects in a collction., if you are concerned about performance.
http://blogs.msdn.com/b/alexj/archive/2009/11/07/tip-41-how-to-execute-t-sql-directly-against-the-database.aspx
You'll probably be better of going to Entity SQL, using a datareader, collection and using custom objects or objects off of the model, if you are concerned about query performance.
https://msdn.microsoft.com/en-us/library/vstudio/bb738684(v=vs.100).aspx
https://msdn.microsoft.com/en-us/library/vstudio/bb387145(v=vs.100).aspx
https://msdn.microsoft.com/en-us/library/vstudio/bb399560(v=vs.100).aspx
My question is if we use both entity framework for parts of the application data access mechanism and enterprise library for other parts of application data access,
are there any known issues?
 A nightmare, no consistency and complete Helter Skelter is what I see. Been there and seen it in action with different technologies doing the same thing in a solution.