Comments on: More Entity Framework thoughts

By: Jimmy Bogard

Jimmy Bogard — Wed, 21 May 2008 01:24:20 +0000

@Darrel

Wanted to reply directly through your blog…oh well, comment will have to do!

First off, I’d like to separate the idea of querying/searching from reporting. These are two different use cases, and most likely different user roles. Perhaps analyst and sales reps for example.

Querying is a valid concern, where I’m returning back one or more entities that belong to you. Writes need to be fast here.

Reporting is a different concern, where I’m returning aggregated, de-normalized information optimized for reading, grouping, and quickly analyzing.

In this scenario, a separate reporting database is definitely a separation of concerns. Reporting users will want their data a certain way. Maybe # of orders this month, grouped by Region, then by State. That’s not something easily done in a transactional manner.

Different users, different user roles, different concerns..that need to be separated? Anyway, most of the time I’ll put the reporting database riiiiight next to the transactional one. Logical != physical modeling, right?

It is an optimization, but an optimization about the “Asks” I’ll get from either user type. The reporting user will want good aggregation, while the querying user wants fast searching (and fast writes). I’d rather not compromise one user’s concerns because it contradicts the other.

Hope this helps!

By: Darrel Miller

Darrel Miller — Tue, 20 May 2008 17:42:48 +0000

“I don’t want reporting concerns bleeding into my transactional concerns”
My problem with this statement is that it sounds a lot like religious zeal.
As far as your users are concerned they want to “report” on their “transactional” data. I would venture to guess that 90% of business apps are running on hardware that has more than enough processing power to transform the transaction data into a reportable format within the required performance constraints.
IMHO building a data warehouse for reporting is a performance optimization, not a seperation of concerns. Making the blanket statement that they should always be seperated is unwise.

By: Patrik Löwendahl

Patrik Löwendahl — Tue, 20 May 2008 15:01:35 +0000

One model to rule them all

http://www.lowendahl.net/showShout.aspx?id=203

By: Bryan Reynolds

Bryan Reynolds — Tue, 20 May 2008 13:53:23 +0000

Good points!

By: DaveTheNinja

DaveTheNinja — Tue, 20 May 2008 01:03:32 +0000

I got $10 on Jimmy!

Dave The Ninja

By: Peter Ritchie

Peter Ritchie — Mon, 19 May 2008 23:23:59 +0000

The whole Order entity from context to context is an excellent point. Only the behaviour of one particular implementation knows that context, the “EDM” can’t and shouldn’t (in case some one’s listening and thinking “if we just add the ability to attribute context to entities and allow them to have the same name these guys will be happy…”) know about that context.

By: Blake C

Blake C — Mon, 19 May 2008 23:20:11 +0000

Jimmy, layin’ the smack down on EF, ftw! Good stuff.