I'm having a few performance bottlenecks in my queries. What happens is whenever i introduce a property as a byte in my entity, EF 4.1 casts it to an int prior to working with it. The given code will explain:
var segmentQuery = workUnit.SegmentRepository.GetQuery()
.Where(x => x.FileId == file.Id)
.Where(x => x.StateValue == (byte)SegmentState.Unhandeled)
.OrderBy(x => x.Index);
Translates nicely to:
SELECT
....
FROM ( SELECT
[Extent1].[Id] AS [Id],
...
[Extent1].[StateValue] AS [StateValue]
FROM [Segments] AS [Extent1]
WHERE ([Extent1].[FileId] = @p__linq__0) AND (0 = [Extent1].[StateValue])
) AS [Project1]
ORDER BY [Project1].[Index] ASC
However, in the case above: StateValue actually is an integer which is way to much for my requirements (4 different states), but when changing it to a byte, i get:
SELECT ...
FROM ( SELECT
[Extent1].[Id] AS [Id],
...
[Extent1].[StateValue] AS [StateValue]
FROM [Segments] AS [Extent1]
WHERE ([Extent1].[FileId] = @p__linq__0) AND (0 = ( CAST( [Extent1].[StateValue] AS int)))
) AS [Project1]
ORDER BY [Project1].[Index] ASC
Since this table might contain more then 100 000 of rows one day, its space efficient (although luckily not essential) for its State field to only occupy 1 byte, however, changing to bytes kill my queries.
Did i do something wrong? Is there anything i can do? is this 'problem' known?
thanks!
** UPDATE **
[Flags]
public enum SegmentState : byte
{
Unhandeled,
Downloaded,
Invalid,
Assembled
}
and in my entity:
/// <summary>
/// Dont use this, use SegmentState instead
/// </summary>
[Required]
public byte StateValue
{
get { return _stateValue; }
set { _stateValue = value; }
}
public SegmentState State
{
get { return (SegmentState)StateValue; }
set
{
if (State != value)
{
StateValue = (byte)value;
RaisePropertyChanged(StatePropertyName);
}
}
}