Linq .Distinct() add extraneous ordering

Question

My entity has a computable geography::point column (represented by DbGeography type in code) When I call a .Distinct() method on query for this entity it adds ORDER BY clause that's ordering by every single column, including the geography::point one, which is not comparable. That leads to an exception. What can be a possible reason for that, and how to fix it?

Query generated by EF before the call to Distinct:

SELECT 
[Project1].[account_key1] AS [account_key], 
...
FROM ( SELECT 
    [Extent1].[account_key] AS [account_key], 
    ...
    CASE WHEN ([Extent9].[object_type] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
    FROM         [dbo].[property_info] AS [Extent1]
    LEFT OUTER JOIN [dbo].[listing_info] AS [Extent2] ON ([Extent1].[property_key] = [Extent2].[property_key]) AND ([Extent1].[account_key] = [Extent2].[account_key])
    LEFT OUTER JOIN [dbo].[v_property_owner_primary_contact] AS [Extent3] ON ([Extent1].[property_key] = [Extent3].[property_key]) AND ([Extent1].[account_key] = [Extent3].[account_key])
    LEFT OUTER JOIN [dbo].[group_info] AS [Extent4] ON ([Extent1].[group_key] = [Extent4].[group_key]) AND ([Extent1].[account_key] = [Extent4].[account_key])
    INNER JOIN [dbo].[user_info] AS [Extent5] ON ([Extent1].[user_key] = [Extent5].[user_key]) AND ([Extent1].[account_key] = [Extent5].[account_key])
    LEFT OUTER JOIN [dbo].[property_types] AS [Extent6] ON ([Extent1].[property_type_key] = [Extent6].[property_type_key]) AND ([Extent1].[account_key] = [Extent6].[account_key])
    LEFT OUTER JOIN [dbo].[listing_info] AS [Extent7] ON ([Extent1].[property_key] = [Extent7].[property_key]) AND ([Extent1].[account_key] = [Extent7].[account_key])
    LEFT OUTER JOIN [dbo].[country_info] AS [Extent8] ON [Extent1].[country_key] = [Extent8].[country_key]
    LEFT OUTER JOIN [dbo].[object_info] AS [Extent9] ON ([Extent1].[property_key] = [Extent9].[property_key]) AND ([Extent1].[account_key] = [Extent9].[account_key])
    WHERE ([Extent1].[account_key] = @p__linq__0) AND ([Extent1].[account_key] = @p__linq__1)
)  AS [Project1]
ORDER BY [Project1].[account_key1] ASC, [Project1].[property_key1] ASC, [Project1].[account_key2] ASC, [Project1].[property_key2] ASC, [Project1].[account_key] ASC, [Project1].[account_key6] ASC, [Project1].[property_key3] ASC, [Project1].[property_key] ASC, [Project1].[account_key3] ASC, [Project1].[group_key1] ASC, [Project1].[account_key4] ASC, [Project1].[user_key2] ASC, [Project1].[account_key5] ASC, [Project1].[property_type_key1] ASC, [Project1].[country_key1] ASC, [Project1].[C2] ASC

Query generated after the Distinct call:

SELECT 
[Project1].[country_key] AS [country_key], 
...
FROM ( SELECT 
    [Extent1].[account_key] AS [account_key], 
    ...
    CASE WHEN ([Extent9].[object_type] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
    FROM         [dbo].[property_info] AS [Extent1]
    LEFT OUTER JOIN [dbo].[listing_info] AS [Extent2] ON ([Extent1].[property_key] = [Extent2].[property_key]) AND ([Extent1].[account_key] = [Extent2].[account_key])
    LEFT OUTER JOIN [dbo].[v_property_owner_primary_contact] AS [Extent3] ON ([Extent1].[property_key] = [Extent3].[property_key]) AND ([Extent1].[account_key] = [Extent3].[account_key])
    LEFT OUTER JOIN [dbo].[group_info] AS [Extent4] ON ([Extent1].[group_key] = [Extent4].[group_key]) AND ([Extent1].[account_key] = [Extent4].[account_key])
    INNER JOIN [dbo].[user_info] AS [Extent5] ON ([Extent1].[user_key] = [Extent5].[user_key]) AND ([Extent1].[account_key] = [Extent5].[account_key])
    LEFT OUTER JOIN [dbo].[property_types] AS [Extent6] ON ([Extent1].[property_type_key] = [Extent6].[property_type_key]) AND ([Extent1].[account_key] = [Extent6].[account_key])
    LEFT OUTER JOIN [dbo].[listing_info] AS [Extent7] ON ([Extent1].[property_key] = [Extent7].[property_key]) AND ([Extent1].[account_key] = [Extent7].[account_key])
    LEFT OUTER JOIN [dbo].[country_info] AS [Extent8] ON [Extent1].[country_key] = [Extent8].[country_key]
    LEFT OUTER JOIN [dbo].[object_info] AS [Extent9] ON ([Extent1].[property_key] = [Extent9].[property_key]) AND ([Extent1].[account_key] = [Extent9].[account_key])
    WHERE ([Extent1].[account_key] = @p__linq__0) AND ([Extent1].[account_key] = @p__linq__1)
)  AS [Project1]
ORDER BY [Project1].[country_key] ASC, [Project1].[account_key] ASC, [Project1].[group_key] ASC, [Project1].[account_key1] ASC, [Project1].[property_key1] ASC, [Project1].[account_key2] ASC, [Project1].[property_key2] ASC, [Project1].[user_key] ASC, [Project1].[property_type_key] ASC, [Project1].[account_key6] ASC, [Project1].[property_key3] ASC, [Project1].[property_key] ASC, [Project1].[rowversion] ASC, [Project1].[rea8_uniqueid] ASC, [Project1].[created_by] ASC, [Project1].[created_date] ASC, [Project1].[modified_by] ASC, [Project1].[modified_date] ASC, [Project1].[verified_by] ASC, [Project1].[verified_date] ASC, [Project1].[site_principal_key] ASC, [Project1].[owner_principal_key] ASC, [Project1].[agent_principal_key] ASC, [Project1].[property_name] ASC, [Project1].[not_mappable] ASC, [Project1].[address_number_1] ASC, [Project1].[address_number_2] ASC, [Project1].[address_direction] ASC, [Project1].[address_street] ASC, [Project1].[address_suite] ASC, [Project1].[padded_number_1] ASC, [Project1].[padded_number_2] ASC, [Project1].[cross_streets] ASC, [Project1].[map_coord] ASC, [Project1].[parcel] ASC, [Project1].[building_id] ASC, [Project1].[description] ASC, [Project1].[web_site] ASC, [Project1].[for_sale] ASC, [Project1].[for_lease] ASC, [Project1].[owner_occupied] ASC, [Project1].[building_class] ASC, [Project1].[construction_type] ASC, [Project1].[location] ASC, [Project1].[zoning] ASC, [Project1].[market] ASC, [Project1].[submarket] ASC, [Project1].[acres] ASC, [Project1].[sqft] ASC, [Project1].[units] ASC, [Project1].[stories] ASC, [Project1].[assessed_value] ASC, [Project1].[last_trans_price] ASC, [Project1].[last_trans_date] ASC, [Project1].[C1] ASC, [Project1].[address_1] ASC, [Project1].[address_2] ASC, [Project1].[city] ASC, [Project1].[state] ASC, [Project1].[zip_code] ASC, [Project1].[latitude] ASC, [Project1].[longitude] ASC, [Project1].[user_1] ASC, [Project1].[user_2] ASC, [Project1].[user_3] ASC, [Project1].[user_4] ASC, [Project1].[user_5] ASC, [Project1].[user_6] ASC, [Project1].[user_7] ASC, [Project1].[user_8] ASC, [Project1].[user_9] ASC, [Project1].[user_10] ASC, [Project1].[user_11] ASC, [Project1].[user_12] ASC, [Project1].[logical_1] ASC, [Project1].[logical_2] ASC, [Project1].[logical_3] ASC, [Project1].[logical_4] ASC, [Project1].[logical_5] ASC, [Project1].[logical_6] ASC, [Project1].[logical_7] ASC, [Project1].[logical_8] ASC, [Project1].[logical_9] ASC, [Project1].[logical_10] ASC, [Project1].[logical_11] ASC, [Project1].[logical_12] ASC, [Project1].[logical_13] ASC, [Project1].[logical_14] ASC, [Project1].[logical_15] ASC, [Project1].[logical_16] ASC, [Project1].[logical_17] ASC, [Project1].[logical_18] ASC, [Project1].[logical_19] ASC, [Project1].[logical_20] ASC, [Project1].[logical_21] ASC, [Project1].[logical_22] ASC, [Project1].[logical_23] ASC, [Project1].[logical_24] ASC, [Project1].[usernumber_1] ASC, [Project1].[usernumber_2] ASC, [Project1].[usernumber_3] ASC, [Project1].[userdate_1] ASC, [Project1].[userdate_2] ASC, [Project1].[userdate_3] ASC, [Project1].[usermulti] ASC, [Project1].[import_source] ASC, [Project1].[import_record] ASC, [Project1].[notes] ASC, [Project1].[geo_point] ASC, [Project1].[account_key3] ASC, [Project1].[group_key1] ASC, [Project1].[account_key4] ASC, [Project1].[user_key2] ASC, [Project1].[account_key5] ASC, [Project1].[property_type_key1] ASC, [Project1].[country_key1] ASC, [Project1].[C2] ASC

You can see that the only thing distinct does is add extraneous orderings

Code that generates a query:

var query = _unitOfWork.Get<T>().AsExpandable();
if (includes != null)
{
    foreach (var include in includes)
    {
        query = query.Include(include);
    }
}
foreach (var queryPredicate in queryPredicateList)
{
    query = query.Where(queryPredicate);
}

query = query.Distinct();

Answer 1

It's because you're changing what's in your projection after you sort the initial results. Distinct doesn't guarantee that the order is preserved.

Incidentally, even if it did work that way, you still wouldn't want to! You'd be sorting through the whole list of items, even though some of them were just going to be thrown out.