Verify the tablespace size.

tablespace_size.sql

SELECT df.tablespace_name                                            AS "Tablespace",
  totalusedspace                                                     AS "Used MB",
  (df.totalspace - tu.totalusedspace)                                AS "Free MB",
  df.totalspace                                                      AS "Total MB",
  ROUND(100 * ( (df.totalspace - tu.totalusedspace)/ df.totalspace)) AS "% Free"
FROM (SELECT tablespace_name,
      ROUND(SUM(bytes) / 1048576) totalspace
    FROM dba_data_files
    GROUP BY tablespace_name) df,
  (SELECT ROUND(SUM(bytes) / 1048576) totalusedspace,
      tablespace_name
    FROM dba_segments
    GROUP BY tablespace_name) tu
WHERE df.tablespace_name = tu.tablespace_name
AND df.totalspace <> 0;