Re: Efficient Integer Comparison Algorithm

From:

Robert Klemme <shortcutter@googlemail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 06 Mar 2008 19:27:33 +0100

Message-ID:

<63arclF258pbgU1@mid.individual.net>

On 06.03.2008 15:48, jeyanthi.m@gmail.com wrote:

Thanks Robert! I now have a better understanding of the problem and a
clear picture on how to proceed.

I am not so sure. Or maybe *I* did not understand everything properly.
Your explanation below seems to deal with three data sources. From
what I read earlier I understood that you have two sources: the Oracle
DB and your local data in a file.

This is what I intend to do based on all your suggestions:
1. Create an external Oracle table for the external file input.
2. Read in records from my local DB in a sorted order and load them as
a pair type into a HashSet.

If you make your local DB available as external table in Oracle then you
can simply do the matching in the DB via a join. The ResultSet from the
join then contains only matching records and you can directly output these.

3. Query the external table and for each row create a temporary
instance of the class and look it up in the set. This is done by
iterating through the ResultSet and local data and comparing each.
a. If the first ordered column in the local store data is less than
in the DB data, increase it until they are same or greater.
b. If same do the same for the second column until a match is found
or the end of one of the two sources is reached.

No. If you have read the local data in a Set or Map already you need to
only look the Oracle data up via the temp instance in the Set / Map. No
additional iterating tricks needed.

4. I would wrap the matches in XML tags and stream it out.

Thanks a lot for all your help!!!

You're welcome.

Kind regards

robert