SDB_Extend - ODABA Extent

Odaba extents are specific collections, which allow storing instances on a database object level in an ODABA database. Extents are properties of object spaces and exist outside of any structure definition. Extents are associated with a structure type, which might refer to VOID type for untypical extents or to the base structure type for weak-typed extents. An extent may define one or more indexes , but must have an identifying key index.

Typically, there is one extent defined, which does not have a base extents. This is called the root extent, which contains all global instances of the given type.