So I was reading the Using Registered Tables vs Object Types design patterns discussion a few months back on EMC Developer Network.
I’m a Documentum old timer, so I was more comfortable using registered tables. Those of you who have used registered tables as lookups knows that its pretty straight forward. Create a table and then REGISTER it so that you can query against it using DQL. The hitch is that if you dont have privileges on the database (or the database is managed by a different group), you are highly dependent on them getting the table schema created with the appropriate permissions. Also, you are dependent on them to move the table and its values from one environment to the next OR you have to have strict version management of table population scripts. Anyways, I have followed this tedious process for many, many years.
After reading the design patterns discussion, I decided for my new project, I would try using object types for lookups. I was not too concerned about security on the objects given that the users were using Taskspace and would not have the ability to delete/manipulate the lookup objects. I created custom type will null supertype, since I wasnt planning to have any content associated with them. See Laurence Hart’s posting on using Contentless Objects as Lookups.
So I created quite a few custom types and created several hundred object instances of my custom lookup types. It was very easy to change the value of the lookups and create new ones using DA or any other Documentum application. Not only did I not have to worry about managing table population scripts, but I did not have to get DBA team involved, since creation of custom object types can be done using DA or DAB. Everything work as expected.
Fast forward a couple of months and now we are ready to deploy our Taskspace application from DEV environment to testing environment. Taskspace was designed to use the docapp archive feature of DAB to move form templates (components), processes, tabs, roles, and presets from one environment to the next.
Lo and behold, DAB does not support the archiving of contentless objects with null supertype. There is no way to include object instances of this kind in docapp archive. This makes sense at object type definition level; if custom type is not derived from dm_sysobject, then it doesnt have i_folder_id attribute, which means the object lives in what I like to call “La La Land”. Application Builder supports the inserting of objects, but it assumes that the object resides in some folder. Unfortunately, there is no “Insert Persistent Objects.”
I havent tried Composer to see if this is supported, but it really was a surprise to me that this feature was not in DAB. In the end I had to remap the custom lookup types to be derived from dm_sysobject. I hope my experience with this will prevent someone from going down the wrong path.