Oracle を使用してテーブルスペースの容量情報をクエリする方法

SELECT tablespace_name, SUM(bytes) AS total_bytes, SUM(bytes - NVL(free.bytes, 0)) AS used_bytes, NVL(free.bytes, 0) AS free_bytes
FROM dba_data_files df
LEFT JOIN (SELECT file_id, SUM(bytes) AS bytes FROM dba_free_space GROUP BY file_id) free
ON df.file_id = free.file_id
GROUP BY tablespace_name;

SELECT file_id, file_name, tablespace_name, bytes, bytes - NVL(free.bytes, 0) AS used_bytes, NVL(free.bytes, 0) AS free_bytes
FROM dba_data_files df
LEFT JOIN (SELECT file_id, SUM(bytes) AS bytes FROM dba_free_space GROUP BY file_id) free
ON df.file_id = free.file_id;

SELECT segment_name, tablespace_name, SUM(bytes) AS total_bytes
FROM dba_segments
GROUP BY segment_name, tablespace_name;