There are two different approaches to work with OODB. The most efficient data storage and retrieval are shown in Example.cs. This approach requires knowing the data structures at compile time. With another approach any object of Hashtable class can be stored/retrieved. The "data fields" in a hashtable do not have to be known at compile time. This approach is less efficient (more storage and processing overhead) but more flexible.
Since Hashtable is a .NET class used in PowerShell, OODB can be worked with from PowerShell as well. This is shown in test.ps1 PowerShell script.
Check the supported data types here: [Data types]
This page [API overview] gives a short overview of the API, however it is recommended to check Example.cs and test.ps1