获取数据库名称：
select NAME from v$database
获取数据库实例名：
select instance_name from v$instance
获取数据库版本：
select value from v$parameter where name='compatible'
获取安装选项：
select OPEN_MODE from v$database
获取归档方式：
select LOG_MODE from v$database
获取归档日志目录：
select name||' value '||value from v$parameter where name = 'log_archive_dest'
获取共享内存大小：
select VALUE from v$parameter where NAME = 'shared_pool_size'
获取操作系统共享内存配置值：
select sum(value) from v$sga
获取回滚段名：
select value from v$parameter where NAME = 'undo_tablespace'
获取回滚段大小：
SELECT sum(bytes/1024/1024) FROM dba_data_files where tablespace_name='UNDOTBS1'
获取session最大连接数：
select count(*) from v$session
获取sga的最大值：
select value from v$sga where name='Variable Size'
获取sga自动管理最大值：
select value from v$parameter where NAME = 'sga_max_size'
获取数据库缓存大小：
select value from v$parameter where name = 'db_cache_size'
获取数据库日志缓存：
select value from v$parameter where name like 'log_buffer'
获取cpu个数：
select value from v$parameter where name = 'cpu_count'
获取数据库总容量：
select sum(a.bytes/1024/1024) from dba_data_files a
获取数据库空闲容量：
select sum(bytes/1024/1024) from dba_free_space
获取oracle位数：
select substr(BANNER,60) from v$version where BANNER like 'Oracle%'
获取数据库锁数量：
select count(*) from v$locked_object
获取数据库锁等待数量：
select count(*) from v$lock where request<>0
获取db buffer cache命中率
SELECT (1 - phy.value / (cur.value + con.value))*100
"CACHE HIT RATIO" FROM v$sysstat cur, v$sysstat con, v$sysstat phy
WHERE cur.name = 'db block gets' AND con.name = 'consistent gets' AND phy.name = 'physical reads'
获取Dictionary Cache 命中率
select (1-( sum(getmisses/1024/1024)/ sum(gets/1024/1024)))*100 from v$rowcache
获取Library Cache 命中率
select gethitratio*100 from v$librarycache where namespace in ('SQL AREA','TABL/PROCEDURE')
获取表空间信息（包括名称、总大小、已使用大小、空余大小）：
SELECT upper(d.tablespace_name),
round(d.total_bytes, 3),
round(d.total_bytes - f.total_free_bytes, 3),
round(f.total_free_bytes, 3),
round((d.total_bytes - f.total_free_bytes) / d.total_bytes * 100, 2)
FROM (SELECT tablespace_name, SUM(bytes) / (1024 * 1024) total_free_bytes
FROM dba_free_space
GROUP BY tablespace_name) f,
(SELECT dd.tablespace_name, SUM(dd.bytes) / (1024 * 1024) total_bytes
FROM dba_data_files dd
GROUP BY dd.tablespace_name) d
WHERE d.tablespace_name = f.tablespace_name
ORDER BY upper(d.tablespace_name)
获取数据文件相关信息：
SELECT df.file_name,df.status,round((df.bytes-sum(fs.bytes))/df.bytes*100,2) FROM dba_free_space fs,dba_data_files df WHERE fs.file_id=df.file_id GROUP BY df.file_name,df.bytes,df.status ORDER BY df.file_name"