Guid default equality comparer

I have a dictionary which maps a Guid to Orders, it contains like 350000 orders

Code:

Dictionary<Guid, Order> htPreOrders = new Dictionary<Guid, PreOrder>(350000);

Im trying to optimize it by replacing the IEqualityComparer by a custom one.

Code:

        class Comp : IEqualityComparer<Guid>
        {
            public bool Equals(Guid x, Guid y)
            {
                return x == y;
            }
            public int GetHashCode(Guid obj)
            {
                return obj.GetHashCode();
            }

Dictionary<Guid, Order> htPreOrders = new Dictionary<Guid, PreOrder>(350000, new Comp());

would this be faster, or is that the same as the default equality comparer of Guid?

I don't see any reason why it would be faster. You need to check if this part of your program actually needs optimization, because you seem to be guessing a lot.

Im learning c# and making software at the same time. So ye Im guessing a lot on how to optimize things but this part needs optimization. Its a database which takes half an hour to retrieve which uses guids for primary keys. But anyway this was not an improvement.

Originally Posted by KIBO

Im learning c# and making software at the same time. So ye Im guessing a lot on how to optimize things but this part needs optimization. Its a database which takes half an hour to retrieve which uses guids for primary keys. But anyway this was not an improvement.

I would doubt it's taking 30 minutes to actually do the comparison(s) needed in a lookup - with the number of objects in your "database" your hash collisions should be relatively small, so most of the lookups will be O(1).
I'd rethink your paradigm - local variables are not intended to replace an actual database; use a real database if you need one.