Question

I have a big Table , about 1 million records , and it’s increasing …..

Now i want retrieve 1K records to a list (List) and do something with it and save results to 3 table (use transaction ) , when these 1k records are handled , how can i know and retrieve again ….

i used Ado.net entity framework as data access module .

I want to use MultiThreading , but i am not very familiar with it.
how can i get this done .

could you give me some sample code or Pseudocode ?

Answer 1

If you’re on .NET 4.0 I would recommend you using the Task Parallel Library to perform any sort of parallel operations.

Here’s an example of how you could use it in your scenario:

IEnumerable<Entity> entities;
int rangeStartIndex = 0;
int rangeLength = 1000;

do
{
    entities = dataContext.Entities
        .Skip(rangeStartIndex)
        .Take(rangeLength);

    Parallel.ForEach(
        entities,
        item =>
        {
            // Process a single entity in the list
        });

    using (var tran = new TransactionScope())
    {
        // Persist the entities in the database
        tran.Complete();
    }

    rangeStartIndex += rangeLength;

} while (entities.Any());

Here we are processing the list of entities in a parallel fashion using the Parallel.ForEach method, without having to worry about managing threads.

Related resources:

• Parallel Methods
• TPL and Traditional .NET Asynchronous Programming