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Efficient Integer Comparison Algorithm

Robert Klemme
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On 06.03.2008 15:48, Removed) 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

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