About VOB namespace
In general, a namespace is a set of unique names. The namespace of a file system usually consists of a hierarchical arrangement of files and directories. Each file and directory has a unique name.
In a VOB, a simple file name is not sufficient to select a single, unique object. For example, prog.c is ambiguous: does it refer to version 1 of prog.c or version 42 of prog.c?
A VOB namespace is the set of file and directory versions that your config spec selects. For example, the view pat_v1.4_cropcircle_sv sees a VOB namespace of the files and directories that contribute to release 1.4 of a software product; the view pat_v1.3_cropcircle_sv sees a VOB namespace of the files and directories that contribute to release 1.3 of the same product. Because versions of directories are tracked, the VOB namespace varies depending on the versions of directories you select.