Managing one-to-too-many relations in rich domain models
88dd106c-94d3-44cf-9b6a-f7b4ef552b3c
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Presentation |
Intermediate
Core Java
Room:
Lab 6
Timeslot:
18.09.08 14:15
Speakers: Eirik Maus and Bjørn Bjerkeli
Abstract:
Domain Driven Design with Object-Relational mapping is the state of
the art for testable object oriented programming in domains with
complex business rules. However, sometimes the domain contains natural
relations and object graphs that are too large to fit in main memory.
Even when you have sufficient memory, working with large object graphs
that are naively OR-mapped can easily give you performance problems.
Bjørn Bjerkeli and Eirik Maus present a few techniques they've used at
BBS to handle the one-to-too-many-relations (almost) without
sacrificing working on a pure domain model. These include domain
object fields based on database queries, iterators that "page"
entities in and out of memory and simplified methods for background
fragment processing.
Outline:
- Problem description
- Relations and collections with Object-Relational Mapping libraries (Hibernate)
- Fix for "running out of time": avoiding needless lazy-loading of large relation set for simple summation
- Fix for running out of memory: Paged Iterations / moving objects out of memory again
- Fix for running out of both time and memory: background fragment processing
- Things we haven't tried yet that we think might work
- Summary
Duration:
50 + 10 min
Language:
The talk can be given in english or norwegian. Slides in english
Level:
Intermediate
Required experience:
Prior exposure to SQL databases and Object Relational mapping is recommended
Expected audience:
Developers and solution architects
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Eirik MausEirik Maus is just a programmer at BBS. He has worked with Bjørn Bjerkeli and several other Javazone speakers on a large project there.
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Bjørn BjerkeliBjørn Bjerkeli currently works as a Senior Consultant in Zenior AS, a Norwegian consulting company. Bjørn has been implementing large-scale distributed systems in Java for insurance companies, banks and major European telecom providers since 1997. He has been working for companies like Nokia and Sybase among others. Although Bjørn often spends much of his time in design and mentoring, he enjoys it when he is engaged in serious coding and development. Bjørn has been member of the program committee for the last three years and is a board member of javaBin. Bjørn writes about his experiences at: http://devperspective.blogspot.com/