Strangely I have not seen any email from Mike Segel. I got a response from Knut Anders. However, compression doesn't seem to be helping. I have tried with 10.4 - but the initial findings are not very satisfactory. Please can you let me know your thoughts on the following questions I sent in my previous email:

I wanted to get
your pulse about whether Derby can respond in sub 100 millisec time with the
table sizes you see above?

I find that:

select category_master.category_name, count(category_master.category_name)
as category_count
               select internal.object_id
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1002) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all
                       values(1001) union all .......
               ) as internal(object_id)

       ) as external_ids,
       external_ids.object_id = object_master.object_id and
       external_ids.object_id = object_category_mapping.
object_id and
       object_master.object_id = object_category_mapping.object_id and
       category_master.category_id = object_category_mapping.category_id
group by
order by
       category_count desc

is much faster unfortunately connection.prepareStatement() is taking way too
much memory (both stack and heap - I have a constraint of 256 MB MAX memory
for my JVM) which goes beyond my applications resources. Is there a way I
can precompile some SQLs which are very expensive to parse during execution.

On Tue, Apr 7, 2009 at 9:36 PM, Bryan Pendleton <> wrote:
What version of Derby? What operating system? What version of Java?
[Arindam]; Windows XP; JRE 1.6

Definitely try using Derby 10.4.

Also, Mike Segel made a bunch of other great suggestions in his mail, so
I suggest following those and see where it gets you.