Question

Let say I have a query with a very large resultset (+100.000 rows) and I need to loop through the and perform an update:

var ds = context.Where(/* query */).Select(e => new { /* fields */ } );

foreach(var d in ds)
{
//perform update
}

I’m fine with this process taking long time to execute but I have limited amount of memory on my server.

What happens in the foreach? Is the entire result fetched at once from the database?

Would it be better to use Skip and Take to do the update in portions?

Answer 1

Best way is to use Skip and Take yes and make sure that after each update, you dispose the DataContext (by using “using”)

You could check out my question, has a similiar problem with a nice solution: Out of memory when creating a lot of objects C#