Forum OpenACS Q&A: ERD for OpenACS/dotLRN

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1: ERD for OpenACS/dotLRN
Posted by Jose Marinez on 05/04/05 09:07 PM
Is there an ERD for OpenACS or dotLRN?

Thanks.

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2: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Juanjo Ruiz on 05/05/05 11:06 AM
I don't think there's such a huge ERD. We are talking about 100-200 tables just the core.

In contrast you have the data base itself (you can just use reverse engineering to get the ERD of the tables you are interested in)
and a pretty good documentation, both general and for every single package (some of them even with an ERD).

For the reverse engineering you have plenty of tools, I would recommend 'Case Studio' and 'Power Designer'.

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3: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Jose Marinez on 05/05/05 02:49 PM
Hi Juanjo,

I'm currently re-evaluating OpenACS. Without an ERD it would be hard to do. I can't believe things have change that much since the days of Arsdigita. Whether the schema has 200 or 500 tables it doesn't really matter. The value of a toolkit like OpenACS lies in its data model. There must be an ERD somewhere.

Thanks Juanjo.

Don, are you around?

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4: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Malte Sussdorff on 05/05/05 02:59 PM
Jose, yes, there existed an ERD some time around. I guess it stretched over ton's of pages and was not useful at all.

As for the changes, they are numerous, but the basics should still be fine. What is more important though for the evaluation as a Toolki is not the datamodell but the API that is provided to access the data modell (in my opinion).

I you want to create an ERD of the core functionality, install OpenACS in PostgreSQL and use http://www.rbt.ca/autodoc/ PostgreSQL autodoc to create a DIA script that you can use for the ERD. I have not tried this way, but I think Joel did it once.

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5: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Deds Castillo on 05/05/05 03:09 PM
I have an email from DaveB stashed in my mailbox containing this info:

====
Here is some of the core data model Data_Model_OpenACS.htm

And some probably too detailed documentation of every table
HTML descriptions https://openacs.org/storage/view/miscellaneous/oacs_5_kernel.html
Graphic of tables and relationships https://openacs.org/storage/view/miscellaneous/oacs_5_kernel.png
and the same graphic as a PDF https://openacs.org/storage/view/miscellaneous/oacs_5_kernel.pdf
====

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6: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Jose Marinez on 05/05/05 03:21 PM
Deds,

Thank you so much for the links. I think this should do. Do you know if this data model and ERD apply to the latest version of OpenACS?

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7: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Jose Marinez on 05/05/05 03:34 PM
Hi Malte,

In your reply you said:

"As for the changes, they are numerous, but the basics should still be fine. What is more important though for the evaluation as a Toolki is not the datamodell but the API that is provided to access the data modell (in my opinion)."

The logic of the toolkit is hidden in its data model. The API is just an abstraction of that logic. However, there may be features and functionality not exposed via the API. The main way to determine that is to bypass the API and evaluate the data model.

The information that Deds provided should be included in the OpenACS' main information page or should be easily accessible.

In any case, thanks for the help in this manner and for the what you've done in the demo site.
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8: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Malte Sussdorff on 05/05/05 04:16 PM
Jose, I'm curious how you will detect things like the database api or the Form/List Builder from the toolkits underlying data model. Same goes for the CR API. If you deal with OpenACS through the CR API you do not have to care how OpenACS looks internally, as this is well hidden from you. And if you use OpenACS as a new developer you should interface the OpenACS core using the API and definitely not storing information directly in the database. But maybe my point of view is wrong, I was just asking myself the question "How does the toolkit help me create my new functionality". For this I think it is more important to evaluate the API than the database models.

On the other hand I have to agree though, that if you want to evaluate the *internals* of OpenACS the ERD should give you the best insights (I'm just thinking about the help this ERD will give us to better understand how to make Dynamic Types work 😊).

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9: Re: ERD for OpenACS/dotLRN (response to 1)
Posted by Jose Marinez on 05/05/05 09:30 PM
Malte,

The OpenACS API seems to be well documented. What I didn't have access to was the ERD and all the other data model documentation. Now that I have both, I'll have everything I need to do a "full examination". At the same time, I may decide not to use certain aspects of the API and create my own implementation (different language, bypass the object model, etc.). In that case, I would want to "dissect" the data model a bit more.

In summary I would say that in order to do a thorough evaluation of any toolkit both the API and the data model should be examined.
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10: Re: Re: ERD for OpenACS/dotLRN (response to 9)
Posted by Malte Sussdorff on 07/05/06 01:50 PM
Does anyone still have the ERD diagrams as storage is not available anymore?