–1、查看表空间的名称及大小 
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、查看表空间物理文件的名称及大小 
SELECT tablespace_name, 
 file_id, 
 file_name, 
 round(bytes / (1024 * 1024), 0) total_space 
 FROM dba_data_files 
 ORDER BY tablespace_name; 
–3、查看回滚段名称及大小 
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$rollstat v 
 WHERE r.segment_id = v.usn(+) 
 ORDER BY segment_name; 
–4、查看控制文件 
SELECT NAME FROM v$controlfile; 
–5、查看日志文件 
SELECT MEMBER FROM v$logfile; 
–6、查看表空间的使用情况 
SELECT SUM(bytes) / (1024 * 1024) AS free_space, tablespace_name 
 FROM dba_free_space 
 GROUP BY tablespace_name; 
 SELECT a.tablespace_name, 
 a.bytes total, 
 b.bytes used, 
 c.bytes free, 
 (b.bytes * 100) / a.bytes "% USED ", 
 (c.bytes * 100) / a.bytes "% FREE " 
 FROM sys.sm$ts_avail a, sys.sm$ts_used b, sys.sm$ts_free c 
 WHERE a.tablespace_name = b.tablespace_name 
 AND a.tablespace_name = c.tablespace_name; 
–7、查看数据库库对象 
SELECT owner, object_type, status, COUNT(*) count# 
 FROM all_objects 
 GROUP BY owner, object_type, status; 
–8、查看数据库的版本  
SELECT version 
 FROM product_component_version 
 WHERE substr(product, 1, 6) = ‘Oracle’; 
–9、查看数据库的创建日期和归档方式 
SELECT created, log_mode, log_mode FROM v$database; 
–1G=1024MB 
 –1M=1024KB 
 –1K=1024Bytes 
 –1M=11048576Bytes 
 –1G=1024*11048576Bytes=11313741824Bytes 
 SELECT a.tablespace_name "表空间名", 
total "表空间大小", 
free "表空间剩余大小", 
 (total – free) "表空间使用大小", 
total / (1024 * 1024 * 1024) "表空间大小(G)", 
 free / (1024 * 1024 * 1024) "表空间剩余大小(G)", 
 (total – free) / (1024 * 1024 * 1024) "表空间使用大小(G)", 
 round((total – free) / total, 4) * 100 "使用率 %" 
FROM (SELECT tablespace_name, SUM(bytes) free 
 FROM dba_free_space 
 GROUP BY tablespace_name) a, 
 (SELECT tablespace_name, SUM(bytes) total 
 FROM dba_data_files 
 GROUP BY tablespace_name) b 
 WHERE a.tablespace_name = b.tablespace_name