Hi

Yes it is an index in dbo.Preguntas. Here it is:

NONCLUSTERED INDEX [Idx] ON [dbo].[Preguntas]

(

[modalidad] ASC,

[examen] ASC,

[asignatura] ASC,

[Pno] ASC

)

INCLUDE ( [codigo_distrito],

[codigo_centro],

[p]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,...

Thanks for your time Lowell, i would keep that in mind.

rvargas

using System.Collections.Generic;

using System.Data.Linq;

using System.Data.Linq.Mapping;

namespace Demo

{

#pragma warning disable 0169 // disable never used warnings for fields that are being used...