--1、查看錶空間的名稱及大小
SELECT t.tablespace_name, round(SUM(bytes / (1024 * 1024)), 0) ts_size
FROM dba_tablespaces t, dba_data_files d
WHERE t.tablespace_name = d.tablespace_name
GROUP BY t.tablespace_name;

--2、查看錶空間物理檔案的名稱及大小
SELECT tablespace_name,
file_id,
file_name,
round(bytes / (1024 * 1024), 0) total_space
FROM dba_data_files

--3、查看回滾段名稱及大小
SELECT segment_name,
tablespace_name,
r.status,
(initial_extent / 1024) initialextent,
(next_extent / 1024) nextextent,
max_extents,
v.curext curextent
FROM dba_rollback_segs r, v$rollstat v
WHERE r.segment_id = v.usn(+)
ORDER BY segment_name;

--4、檢視控制檔案
SELECT NAME FROM v$controlfile;

--5、檢視日誌檔案
SELECT MEMBER FROM v$logfile;

--6、查看錶空間的使用情況
SELECT SUM(bytes) / (1024 * 1024) AS free_space, tablespace_name
FROM dba_free_space
GROUP BY tablespace_name;
SELECT a.tablespace_name,
a.bytes total,
b.bytes used,
c.bytes free,
(b.bytes * 100) / a.bytes "% USED ",
(c.bytes * 100) / a.bytes "% FREE "
FROM sys.sm$ts_avail a, sys.sm$ts_used b, sys.sm$ts_free c

--7、檢視資料庫庫物件
SELECT owner, object_type, status, COUNT(*) count#
FROM all_objects
GROUP BY owner, object_type, status;

--8、檢視資料庫的版本
SELECT version
FROM product_component_version
WHERE substr(product, 1, 6) = 'Oracle';

--9、檢視資料庫的建立日期和歸檔方式
SELECT created, log_mode, log_mode FROM v$database;