Tblspace table
he tblspace table tracks all active tblspaces in a database server instance.
TAn active tblspace is one that is currently in use by a database session. Each active table accounts for one entry in the tblspace table. Active tblspaces include database tables, temporary tables, and internal control tables, such as system catalog tables. Each tblspace table entry includes header information about the tblspace, the tblspace name, and pointers to the tblspace tblspace in dbspaces on disk. (The shared-memory active tblspace table is different from the tblspace tblspace.) For information about monitoring tblspaces, see Monitor tblspaces and extents.
The database server manages one tblspace table for each dbspace.