Preprocess data for reporting

Question

we have in house J2EE reporting application, which fetches data from 2 separate databases which may have duplicate day. so we fetch data from 2 database removes duplication and then calculate numbers on the bases of daily, weekly, monthly and yearly bases.

As expected it takes time from 2 minutes to an hour :)

So now my task is to improve the performance, i wants to write new J2EE web application application.

I have complex join queries which can process/populate data, and i can put them into new table so when we run parameter queries to pull data according to my need and that will be much faster.

Please give me your opinion, and if some has advise for me.

Answer 1

This is a very general question with potential bottlenecks in several places :

• DB
• JAVA code
• JVM configuration
• Network

The first advice would be to determine where the time is spent during that processing and then ask SO concrete questions about how to improve each point.