Question

I recently had to troubleshoot a performance problem with a slow grid load. Upon investigation, it looked like someone had used a List<Product> to populate the grid. The problem was that the Product object had a lot of properties, many of them not.lazyloads(), most of them not even needed for the grid.

So to resolve the issue I created a new Object called ProductLite, that had only lazy loads, most of the key info on joins and the performance was now great. Rather than doing 10,000 db hits, it went to 1.

My question to the SO community, how do you model your objects? I was thinking that all objects should have a “details” and “info” versions, since sometimes and intensive object load is needed. Ie. ProductDetails would contain all the info and not be used in lists, whereas ProductInfo would carry simply the high level info for use in lists, quick lookups etc.

Is there a standard that has been adopted as a best-practice for modeling objects?

Answer 1

The problem here is that you are confusing Domain Model objects with DTOs/Presentation Model objects.

I’m usually reluctant to consider any guideline a “best practice”, but here are a few general tips:

• Domain objects should be one per table (not considering inheritance)
• Lazy loading should not be disabled in the mappings. Good article about this.
• Use reasonable batch-size settings for entities and collections (rule of thumb: use your page size)
• Use caching, at least for mostly-read-only objects
• Use projections (anonymous, typed, object arrays, whatever works) if you really need to load just a few fields of many objects, when you don’t need to edit an object