查詢各表 總筆數(總列數) 使用量(大小)

SELECT USER_TABLES.TABLE_NAME ,num_rows 列數 ,
SUM(BYTES) / (1024 * 1024) AS "size(M)"
FROM USER_TABLES,
USER_SEGMENTS WHERE USER_SEGMENTS.SEGMENT_NAME = USER_TABLES.TABLE_NAME
GROUP BY USER_TABLES.TABLE_NAME,num_rows
ORDER BY "size(M)" DESC