Sunday, March 15, 2009

Daylight Savings Time

After the DST time change on March 7, 2009, we discovered that certain events in the playlist generated from S4M were out of chronological order. To compensate for this, I made a change to the playlist translator so when it converted the S4M H-class file to the DAL playout server format, all the events would be sorted in chronological order, from 6AM to 5:59AM the following day (broadcast time).

Sunday, March 1, 2009

Understanding the r_object_id

Although this post is more specific to EMC Documentum, I want to cover off this information as it is difficult to locate on the web, plus Documentum is a system of great value to broadcasters.

Documentum is an Enterprise Content Management (ECM) system which stores unstructured data as objects in its repository. These data include images, music, movies and any type of electronic file or record you can think of. Each of these objects in Documentum has its own unique and persistant identifier, known as the r_object_id. Even different versions of the same content have their own unique r_object_id.

What is not advertised much on the web is what the r_object_id means. Yes, it is an unique persistent identifier, but it also tells the type of Documentum object it represents, as well as the repository where the object is located.

The r_object_id is a 16 digit hexadecimal number. For example 0900055080007f1c is a valid r_object_id.

The first 2 digits, 09 in this example, are the tag, which indicate the type of Documentum object. Obviously, because Documentum supports custom types which inherit from the Documentum super type, there can be an immense number of types in the repository. Therefore, the tag only identifies the Documentum super type that the object is of or what it is inherited from. The tags and what Documentum super types they refer to are listed below:
09 dm_document
08 dm_sysobject, dm_script, dm_query
06 dmr_content
05 dmr_containment
41 dm_note
0c dm_cabinet
0b dm_folder
11 dm_user
12 dm_group
18 dm_router
19 dm_registered
27 dm_format
0d dm_assembly
3a dm_location

The other parts of the r_object_id, the repository id and the unique id generated by the server, are self explanatory.
This information is covered in the Technical Fundamentals of Documentum course and manual, but oftentimes we throw those manuals away or lose them. :)