CSDM (and other ServiceNow tables) documentation?

[dbcandle]

Is there a good *complete* reference of the CSDM and all other ServiceNow tables?  When I asked this question back in 2017, CSDM was new, and there was not a good answer.

My background is that of a database administrator (Oracle & SQL Server), developer, and data architect.  I'm use to ready access to data models.  With ServiceNow, I pretty-much gave-up because it was so hard to get "up-to-speed" with the data model, but 6 years later, I'd like to try again.

We're using the San Diego version of ServiceNow.  What I am really looking for is good PDF documentation describing the data-model (CSDM, CMDB, CI, etc.): everything.

Note: Here's an old thread I created 6 years ago.  I'm hoping things have changed! Re: Database (Tables) Documentation? - ServiceNow Community

[CMDB Whisperer · Accepted solution]

I think the short answer is: not exactly.

From a purely data modeling perspective, CSDM probably won't give you what you are looking for.  It is certainly useful for CMDB practitioners, and does provide practical guidance on how to use the different tables and CI classes to get the best value from the platform.  But if you are looking for how this works from a technical database management perspective it's not going to give you a thorough description of the ServiceNow data model.  Even for just the CMDB tables -- of which there are around a thousand, give or take a couple hundred -- CSDM is really just focused on the 10 or 20 classes that represent the logical business layer, not the infrastructure CIs.  That said, CSDM is an extremely important framework for CMDB practitioners and other process owners to be aware of, and you can find the official documentation for it in both the Product Documentation and here in the Community.  The current version is 4.0, and you can find the official documentation here.  Ignore the fact that it says "DRAFT"; there won't be another version of the 4.0 document.  They are working on 5.0 and there is no projected date for when that will be available.

As for how to get official descriptions of the table or fields, you won't find a definitive place for this documentation anywhere.  Not even for CMDB.  They have introduced a table that allows class descriptions and other metadata to be specified, but only for the CMDB classes, and unfortunately they didn't provide retroactive descriptions for the OOB classes, and have only provided descriptions for the CI Classes that are distributed via the CMDB CI Class Models plugin.  You can find additional descriptions for the CI Classes in the Product Documentation and if desired you can load these into your CI Class metadata table for easy reference.

And to my knowledge there is no definitive up-to-date ERD that will help you to understand the table relationships.  A company called Nashco put one together several years ago, but it should not be considered definitive.  Several areas reference incorrect table names, and certainly it is missing tables.  But check it out if you haven't, because it still provides some educational value for those who want to understand how the data model works in ServiceNow.

[dbcandle]

Much appreciated! 😊