I've got a UDF that is used on the publishing side of a data warehouse:
when the data is headed out to a mart.  It works fine for sets of a few
thousand rows, but really slows for sets of a few million rows:  a
query will go from one to thirty minutes due to two calls on each row.
Any suggestions or advise?

-----------------------------------------------------------------------------
-- convert ip from integer format to string format
-- ex:  from 3232235621 to 192.168.0.101
-----------------------------------------------------------------------------
create function IP2STRING(IP_BIGINT bigint)
  returns varchar(15)
  deterministic
  no external action
begin atomic
declare node_1      bigint;
declare node_2      bigint;
declare node_3      bigint;
declare node_4      bigint;
SET node_1        = MOD(BIGINT(ip_bigint / 16777216), 256);
SET node_2        = MOD(INTEGER(ip_bigint  / 65536), 256);
SET node_3        = MOD(INTEGER(ip_bigint / 256), 256);
SET node_4        = MOD(ip_bigint, 256);
return RTRIM(CHAR(node_1)) || '.' || RTRIM(CHAR(node_2)) || '.' ||
RTRIM(CHAR(node_3)) || '.' ||  RTRIM(CHAR(node_4));
end

Am I missing any good opportunities to speed this up?
Any faster algorithm or functions to switch to?
Or should I consider a java routine with bitfiddling (yuck)?
Or give up on this approach and move the logic out of the database
(dang)?

Thanks in advance!

Ken