The V$, V_$, GV$ and GV_$ views are known as the ‘dynamic performance tables’ (DPT). They are called this because they have no physical existence in the database and are constantly changing (hence â€œdynamicâ€) views of the database system. Each time one of these views is accessed, it provides a snapshot for that moment in time of the database status.
The V_$ tables are actually views against the GV_$ tables. The only difference being that the GV (Global View) views include the instance value for systems using the parallel server option.
Most general database users usually don’t need to access these DPTs. Some DPTs, like the V_$DATABASE view, do contain useful information, such as the Oracle version and database name, for general users.
Note: Unlike the DBA views, the DPT views do not store a general description of their purpose or column definitions in the Data Dictionary.