transactions

set transaction isolation level repeatable read

begin tran

select * from Relationship where link_id=64099

commit tran

set transaction isolation level repeatable read

begin tran

update Relationship set start_date='2012-12-06' from Relationship where link_id=64099

commit tran

set transaction isolation level read committed

begin tran

select * from Relationship where link_id=64099

commit tran

set transaction isolation level read committed

begin tran

update Relationship set start_date='2012-12-06' from Relationship where link_id=64099

commit tran

NOLOCK VS ReadPast

select * from Relationship(nolock) where link_id=64099

select * from Relationship(readpast) where link_id=64099