Saturday, December 09, 2006
Single vs Multiple Database ArcSDE
Posted on Saturday, December 09, 2006 6:44:53 PM (Mountain Standard Time, UTC-07:00)  Comments [1] | 
Categories: ArcSDE
Ron Bruder & Derek Swingley pointed out that I had misunderstood the Single vs Multiple database thing, and the relationship to SDE vs DBO owned schema.

Since I missed this, and I've been using SDE since before they attached "Arc" to the front of it, I'm guessing some other people may have missed this as well (or like me, skipped reading the 9.2 documentation!).

My Logic (Wrong!)
I has assumed that the "single" and "multiple" were referring to the SDE system table repository.  Thus,  the "Single" database model  was  the traditional model where the system table repository was in one database - "SDE".  Additionally, I had assumed that "multiple" referred to  storing the table repository in multiple databased.  This is completely backwards.


How it REALLY works

Ron posted a link to a Forum posting by Derek, in which Derek posted a link to the explanation of this on the ArcSDE  on-line docs.  Since pictures are worth a 1000 words, I've linked the diagrams from that site here  (disclosure: these are ESRI diagrams, hosted @ EDN.)


Single Database Model



This is the "default" and recommended model at 9.2.


Multiple Database Model


This is the traditional model with the SDE table repository in the SDE database.

SDE & DBO schema
You can use either SDE or DBO schema with both "single" and "multiple". Derek also provided a link to web help on this topic.

Thanks for getting me on the right track with this!
Saturday, December 09, 2006 9:15:18 PM (Mountain Standard Time, UTC-07:00)
Always glad to help. I'll just add a little more background info. The multiple database option was the only way to do it before 9.0. 9.0 introduced the single database model and made it the default. 9.2 didn't change or add anything other than improved documentation.
Derek Swingley
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