multi-threading batch updates, how to get unique identifiers

                                                                                                                                                                                                                                                  
create procedure My_unique
(
 @table_id int,
 @incr     int,
 @unique   int output
)
as

/*
 * %W%    %D%
 * Get a block of incr unique id's for table with ID table_id.
 * Returns first ID in the block.
 */

select @unique = -999
if @incr < 1
begin
    
 select error_status = "Must set increment > 0"
    return @unique
end
if @table_id = 103
begin
begin transaction
    update tradeControl
    set    tradeId = tradeId + @incr
    select @unique = tradeId - @incr
    from   tradeControl
commit transaction
 
return @unique
end
else if @table_id = 100
begin
begin transaction
    update STPIdCtrl
    set id = id + @incr
    where STPFieldName = 'eventId'
    select @unique = id - @incr
    from STPIdCtrl
    where STPFieldName = 'eventId'
commit transaction
ret
urn @unique
end
else if @table_id = 101
begin
begin transaction
    update STPIdCtrl
    set id = id + @incr
    where STPFieldName = 'ticketId'
    select @unique = id - @incr
    from STPIdCtrl
    where STPFieldName = 'ticketId'
commit transaction
retu
rn @unique
end
else if @table_id = 104
begin
begin transaction
    update STPIdCtrl
    set id = id + @incr
    where STPFieldName = 'updateId'
    select @unique = id - @incr
    from STPIdCtrl
    where STPFieldName = 'updateId'
commit transaction
retur
n @unique
end
else if @table_id = 110
begin
begin transaction
    update TDSIdCtl
    set updateId = updateId + @incr
    select @unique = updateId
    from TDSIdCtl
commit transaction
return @unique
end
else if @table_id = 14
begin
begin transaction
    select @uniq
ue = ord_grouping_id
    from   CDM_ord_groupings_ctrl holdlock
    update CDM_ord_groupings_ctrl
    set    ord_grouping_id = ord_grouping_id + @incr
commit transaction
end
else if @table_id = 27
begin
begin transaction
    select @unique = order_id
 
   from   CDM_order_ctrl holdlock
    update CDM_order_ctrl
    set    order_id = order_id + @incr
commit transaction
end
else if @table_id = 28
begin
begin transaction
    select @unique = execution_id
    from   CDM_execution_ctrl holdlock
    update  
CDM_execution_ctrl
    set    execution_id = execution_id + @incr
commit transaction
end
else if @table_id = 26
begin
begin transaction
    update CDM_position_ctrl
    set    position_id = position_id + @incr
    select @unique = position_id - @incr
   
  from   CDM_position_ctrl
commit transaction
end
else if @table_id = 18
begin
    select @unique = volatility_id
    from   CDM_volatility_ctrl holdlock
    update CDM_volatility_ctrl
    set    volatility_id = volatility_id + @incr
end
else if @table
_id = 20
begin
begin transaction
    update CDM_yield_ctrl
    set    yield_id = yield_id + @incr
    select @unique = yield_id - @incr
    from   CDM_yield_ctrl
commit transaction
end
else if @table_id = 22
begin
begin transaction
    update CDM_divide
nd_ctrl
    set    dividend_id = dividend_id + @incr
    select @unique = dividend_id - @incr
    from   CDM_dividend_ctrl
commit transaction
end
else if @table_id = 29
begin
begin transaction
    update CDM_underlying_ctrl
    set    underlying_id = u
nderlying_id + @incr
    select @unique = underlying_id - @incr
    from   CDM_underlying_ctrl
commit transaction
end
else if @table_id = 19 or @table_id = 102
begin
begin transaction
    update CDM_yield_list_ctrl
    set    yield_list_id = yield_list_
id + @incr
    select @unique = yield_list_id - @incr
    from   CDM_yield_list_ctrl
commit transaction
end
else if @table_id = 21
begin
begin transaction
    update CDM_dividend_list_ctrl
    set    dividend_list_id = dividend_list_id + @incr
    selec
t @unique = dividend_list_id - @incr
    from   CDM_dividend_list_ctrl
commit transaction
end
else if @table_id = 95
begin
begin transaction
    update CDM_borrow_detail_ctrl
    set    borr_id = borr_id + @incr
    select @unique = borr_id - @incr
     
from   CDM_borrow_detail_ctrl
commit transaction
end
else if @table_id = 96
begin
begin transaction
    update CDM_borrow_list_ctrl
    set    borr_list_id = borr_list_id + @incr
    select @unique = borr_list_id - @incr
    from   CDM_borrow_list_ctrl  

commit transaction
end
else if @table_id = 55
begin
    select @unique = execution_log_id
    from   CDM_execution_log_ctrl holdlock
    update CDM_execution_log_ctrl
    set    execution_log_id = execution_log_id + @incr
end
else if @table_id = 58
beg
in
    select @unique = reut_mask_id
    from   CDM_reuters_masks_ctrl holdlock
    update CDM_reuters_masks_ctrl
    set    reut_mask_id = reut_mask_id + @incr
end
return @unique