怎么查看oracle11g表空间的使用情况

你可以使用以下SQL语句查看Oracle 11g数据库表空间的使用情况：

SELECT
    tablespace_name,
    ROUND(SUM(bytes) / 1024 / 1024, 2) total_space_mb,
    ROUND(SUM(bytes - NVL(free_space, 0)) / 1024 / 1024, 2) used_space_mb,
    ROUND(NVL(free_space, 0) / 1024 / 1024, 2) free_space_mb,
    ROUND((SUM(bytes - NVL(free_space, 0)) / SUM(bytes)) * 100, 2) pct_used
FROM
    (SELECT
        tablespace_name,
        SUM(bytes) bytes
    FROM
        dba_data_files
    GROUP BY
        tablespace_name
    UNION ALL
    SELECT
        tablespace_name,
        SUM(bytes)
    FROM
        dba_temp_files
    GROUP BY
        tablespace_name
    ) fs,
    (SELECT
        tablespace_name,
        SUM(bytes) free_space
    FROM
        dba_free_space
    GROUP BY
        tablespace_name
    ) bfs
WHERE
    fs.tablespace_name = bfs.tablespace_name(+)
GROUP BY
    tablespace_name, free_space
ORDER BY
    tablespace_name;

这个SQL语句会返回一个表，其中包含了每个表空间的名称、总空间、已用空间、剩余空间、以及已用百分比等信息。