SELECT
  TABLESPACE_ID,                           -- TABLESPACE_ID NUMBER
  RFNO,                                    -- RFNO NUMBER
  ALLOCATED_SPACE,                         -- ALLOCATED_SPACE NUMBER
  FILE_SIZE,                               -- FILE_SIZE NUMBER
  FILE_MAXSIZE,                            -- FILE_MAXSIZE NUMBER
  CHANGESCN_BASE,                          -- CHANGESCN_BASE NUMBER
  CHANGESCN_WRAP,                          -- CHANGESCN_WRAP NUMBER
  FLAG                                     -- FLAG NUMBER
FROM
  GV$FILESPACE_USAGE
WHERE
  INST_ID = USERENV('INSTANCE')