Collection List object performance

[piusfernandez]

I have a situation in Java Collection and i am not able to figure a good solution. I am scared about the performance and memory that wil be used

I have 5 List objects with thousands and thousands of records in it. The List is populated by a database query using jdbcTemplate which return like 200,000 records

Each record is identified by POLICY_ID. They may be List with multiple records for a POLICY_ID

I want to extract each POLICY_ID from all the 5 List and make a single List object for each POLICY_ID and for each List and pass it to a print job which will print the data for a POLICY_ID

Example
Let say we have POLICY_ID = 15432

List1 has one record for 15432
List2 has one record for 15432
List3 has one record for 15432
List4 has three record for 15432
List5 has three record for 15432

From the 200,000 records in List1 i want to generate a seperate list with 1 record for policy id 15432 and let name is Listperpolicy
after this logic we have
Listperpolicy1
Listperpolicy2
Listperpolicy3
Listperpolicy4
Listperpolicy5

Can you please guide me on the approach i should take to write a better code

call print job ( Listperpolicy1, Listperpolicy2, Listperpolicy3, Listperpolicy4, Listperpolicy5)

Please let me know

Thanks a Lottttttttt

[aniseed]

I have 5 List objects with thousands and thousands of records in it. The List is populated by a database query using jdbcTemplate which return like 200,000 records

Maybe you are taking the wrong approach at the beginning. A good design would eliminate the need to fetch all those records.

[nspils]

Why do you need to create a series of lists if you are getting these records from a database? Shouldn't you have your query populate a Table?

As aniseed suggested, perhaps you should be looking at your problem from another angle. How about creating a class of PolicyHolder, identified with a PolicyHolder_ID of some sort, holding an array or vector of [Policy_ID records]. Search for policy holder, extract the policy/policies. of course, this is dependent upon your needs and your skill at generating queries from your database ...