Reputation: 1499
In Sql Developer under tables I see tables, but some of the tables have $ in name.
Example:
tb$something
What does that '$' sign mean when in name of table?
Upvotes: 16
Views: 20161
Reputation: 3211
Tables that contain the prefix V$ are tables that store volatile information.
Volatile information is produced by an oracle instance while it is in use (In use means the instance is up and running). Volatile Information includes Statistics, session information of users, memory allocation.
Upvotes: 11
Reputation: 30845
Usually, these are tables that "belong" to the database - either because they are owned by one of the predefined users (SYS, ...) or because Oracle uses them for housekeeping, e.g. for
But you can't rely on that rule, because (as DazzaL already mentioned), nothing prevents you from creating your own tables with a dollar sign in the name.
Upvotes: 6
Reputation: 21993
it doesn't mean anything. as you can create tables with dollar signs in if you want (probably not recommended as people may get confused thinking they are oracle special tables).
if you're referring to objects owned by SYS
and SYSTEM
then Oracle names its memory structure views for example V$
(eg v$session
). but these are just a naming convention that Oracle corp uses for its objects.
Upvotes: 12