-- SETUP

  drop table dbo.myqueue

  create table dbo.myqueue (
    itemId int identity primary key clustered,
    worker varchar(32) null,
    myguid uniqueidentifier null,
    work_timeout datetime null,
    picture_to_resize nvarchar(128) not null, 
  )

  -- ENQUEUE WORK

  insert dbo.myqueue(picture_to_resize) values('Kitten.jpg')
  insert dbo.myqueue(picture_to_resize) values('Doggy.jpg')

  -- PROCESS WORK FROM QUEUE

  declare @worker varchar(32)  = 'worker-21'
  declare @guid uniqueidentifier = newid()
  update t set 
    t.worker = @worker, 
    t.work_timeout = DATEADD(minute, 30, getdate()),
    t.myguid = @guid
  from 
    (select top 1 * from dbo.myqueue 
      where work_timeout is null or work_timeout<getdate()
      order by itemId asc
    ) t

  select * from dbo.myqueue where myguid=@guid
  
  -- If nothing found, client should retry...

  -- UPDATE TIMEOUT AS PROGRESS IS MADE
  -- Don't update if another worker stole our job!

  update t set t.work_timeout =DATEADD(minute, 30, getdate())
    from dbo.myqueue t where myguid=@guid and t.worker=@worker


  -- WHEN WORK IS DONE, ITEM SHOULD BE DELETED/ARCHIVED...