where a.statisti c# = 38 and b.statistic# = 39
and c.statistic# = 40;
151. 如何监控SGA 中字典缓冲区的命中率？
select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",
(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"
from v$rowcache
where gets+getmisses <>0
group by parameter, gets, getmisses;
152. 如何监控SGA 中共享缓存区的命中率，应该小于1% ？
select sum(pins) "Total Pins", sum(reloads) "Total Reloads",
sum(reloads)/sum(pins) *100 libcache
from v$librarycache;
select sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent"
from v$librarycache;
153. 如何显示所有数据库对象的类别和大小？
select count(name) num_instances ,type ,sum(source_size) source_size ,
sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,
sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required
from dba_object_size
group by type order by 2;
154. 监控SGA 中重做日志缓存区的命中率，应该小于1%
SELECT name, gets, misses, immediate_gets, immediate_misses,
Decode(gets,0,0,misses/gets*100) ratio1,
Decode(immediate_gets+immediate_misses,0,0,
immediate_misses/(immediate_gets+immediate_misses)*100) ratio2
FROM v$latch WHERE name IN ('redo allocation', 'redo copy');
155. 监控内存和硬盘的排序比率，最好使它小于.10，增加sort_area_size
SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts(disk)');
156. 如何监控当前数据库谁在运行什幺SQL语句？
SELECT osuser, username, sql_text from v$session a, v$sqltext b
where a.sql_address =b.address order by address, piece;
157. 如何监控字典缓冲区？
SELECT (SUM(PINS - RELOADS)) / SUM(PINS) "LIB CACHE" FROM V$LIBRARYCACHE;
SELECT (SUM(GETS - GETMISSES - USAGE - FIXED)) / SUM(GETS) "ROW CACHE" FROM V$ROWCACHE;
SELECT SUM(PINS) "EXECUTIONS", SUM(RELOADS) "CACHE MISSES WHILE EXECUTING" FROM V$LIBRARYCACHE;
后者除以前者,此比率小于1%,接近0%为好。
FROM V$ROWCACHE
158. 监控MTS
select busy/(busy+idle) "shared servers busy" from v$dispatcher;
此值大于0.5时，参数需加大
select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type='dispatcher';
select count(*) from v$dispatcher;
select servers_highwater from v$mts;
servers_highwater接近mts_max_servers时，参数需加大
159. 如何知道当前用户的ID号
SQL>SHOW USER;
OR
SQL>select user from dual;
160. 如何查看碎片程度高的表
SELECT segment_name table_name , COUNT(*) extents
FROM dba_segments WHERE owner NOT IN ('SYS', 'SYSTEM') GROUP BY segment_name
HAVING COUNT(*) = (SELECT MAX( COUNT(*) ) FROM dba_segments GROUP BY segment_name);
162. 如何知道表在表空间中的存储情况
select segment_name,sum(bytes),count(*) ext_quan from dba_extents where
tablespace_name='&tablespace_name' and segment_type='TABLE' group by tablespace_name,segment_name;
163. 如何知道索引在表空间中的存储情况
select segment_name,count(*) from dba_extents where segment_type='INDEX' and owner='&owner'
group by segment_name;
164、如何知道使用CPU多的用户session
11是cpu used by this session
select a.sid,spid,status,substr(a.program,1,40) prog,a.terminal,osuser,value/60/100 value
from v$session a,v$process b,v$sesstat c
where c.statistic#=11 and c.sid=a.sid and a.paddr=b.addr order by value desc;
165. 如何知道监听器日志文件
以8I为例
$ORACLE_HOME/NETWORK/LOG/LISTENER.LOG
166. 如何知道监听器参数文件
以8I为例
$ORACLE_HOME/NETWORK/ADMIN/LISTENER.ORA
167. 如何知道TNS 连接文件
以8I为例
$ORACLE_HOME/NETWORK/ADMIN/TN