use tempdb;
go

create table dbo.t1 (id uniqueidentifier primary key);
create table dbo.t2 (id uniqueidentifier primary key);
create table dbo.t3 (id varchar(36) primary key);
create table dbo.t4 (id varchar(36) primary key);
create table dbo.t5 (id varchar(36) collate Cyrillic_General_BIN primary key);
create table dbo.t6 (id varchar(36) collate Cyrillic_General_BIN primary key);
go

insert into dbo.t1
 (id)
 output inserted.id into dbo.t2
 select top (1000000)
  newid()
 from
  master.dbo.spt_values a cross join
  master.dbo.spt_values b;

insert into dbo.t3
 (id)
 select cast(id as varchar(36)) from dbo.t1;

insert into dbo.t4
 (id)
 select cast(id as varchar(36)) from dbo.t1;

insert into dbo.t5
 (id)
 select cast(id as varchar(36)) from dbo.t1;

insert into dbo.t6
 (id)
 select cast(id as varchar(36)) from dbo.t1;
go

declare @c int;
set statistics time on;
select @c = count(*) from dbo.t1 join dbo.t2 on t2.id = t1.id option (maxdop 1);
select @c = count(*) from dbo.t3 join dbo.t4 on t4.id = t3.id option (maxdop 1);
select @c = count(*) from dbo.t5 join dbo.t6 on t5.id = t6.id option (maxdop 1);
set statistics time off;
go

drop table dbo.t1, dbo.t2, dbo.t3, dbo.t4, dbo.t5, dbo.t6;
go

 Время работы SQL Server:
   Время ЦП = 218 мс, затраченное время = 214 мс.

 Время работы SQL Server:
   Время ЦП = 1139 мс, затраченное время = 1139 мс.

 Время работы SQL Server:
   Время ЦП = 281 мс, затраченное время = 284 мс.

use tempdb;
go

create table dbo.t1 (id uniqueidentifier primary key);
create table dbo.t2 (id uniqueidentifier primary key);
create table dbo.t3 (id varchar(16) primary key);
create table dbo.t4 (id varchar(16) primary key);
create table dbo.t5 (id varchar(16) collate Cyrillic_General_BIN primary key);
create table dbo.t6 (id varchar(16) collate Cyrillic_General_BIN primary key);
create table dbo.t7 (id char(16) primary key);
create table dbo.t8 (id char(16) primary key);
go

insert into dbo.t1
 (id)
 output inserted.id into dbo.t2
 select top (1000000)
  newid()
 from
  master.dbo.spt_values a cross join
  master.dbo.spt_values b;

insert into dbo.t3
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;

insert into dbo.t4
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;

insert into dbo.t5
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;

insert into dbo.t6
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;
go

insert into dbo.t7
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;
go

insert into dbo.t8
 (id)
 select left(cast(id as varchar(36)), 16) from dbo.t1;
go

declare @c int;
set statistics time on;
select @c = count(*) from dbo.t1 join dbo.t2 on t2.id = t1.id option (maxdop 1);
select @c = count(*) from dbo.t3 join dbo.t4 on t4.id = t3.id option (maxdop 1);
select @c = count(*) from dbo.t7 join dbo.t8 on t7.id = t8.id option (maxdop 1);
select @c = count(*) from dbo.t5 join dbo.t6 on t5.id = t6.id option (maxdop 1);
set statistics time off;
go

drop table dbo.t1, dbo.t2, dbo.t3, dbo.t4, dbo.t5, dbo.t6, dbo.t7, dbo.t8;
go