DBA数据库信息查询常用SQL

常用DBA脚本
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;

10、捕捉运行很久的SQL
column username format a12
column opname format a16
column progress format a8

select username,sid,opname,
round(sofar*100 / totalwork,0) || ‘%‘ as progress,
time_remaining,sql_text
from v$session_longops , v$sql
where time_remaining <> 0
and sql_address = address
and sql_hash_value = hash_value

11、查看数据表的参数信息
SELECT partition_name, high_value, high_value_length, tablespace_name,
pct_free, pct_used, ini_trans, max_trans, initial_extent,
next_extent, min_extent, max_extent, pct_increase, FREELISTS,
freelist_groups, LOGGING, BUFFER_POOL, num_rows, blocks,
empty_blocks, avg_space, chain_cnt, avg_row_len, sample_size,
last_analyzed
FROM dba_tab_partitions
--WHERE table_name = :tname AND table_owner = :towner
ORDER BY partition_position

12.查看还没提交的事务
　　select * from v$locked_object;
　　select * from v$transaction;

13.查找object为哪些进程所用
select
p.spid,
s.sid,
s.serial# serial_num,
s.username user_name,
a.type object_type,
s.osuser os_user_name,
a.owner,
a.object object_name,
decode(sign(48 - command),
1,
to_char(command), ‘Action Code #‘ || to_char(command) ) action,
p.program oracle_process,
s.terminal terminal,
s.program program,
s.status session_status
from v$session s, v$access a, v$process p
where s.paddr = p.addr and
s.type = ‘USER‘ and
a.sid = s.sid and
a.object=‘SUBSCRIBER_ATTR‘
order by s.username, s.osuser

14.回滚段查看
select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents
Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs,
v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes,
sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs,
v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and
v$rollstat.usn (+) = v$rollname.usn order by rownum

15.耗资源的进程（top session）
select s.schemaname schema_name, decode(sign(48 - command), 1,
to_char(command), ‘Action Code #‘ || to_char(command) ) action, status
session_status, s.osuser os_user_name, s.sid, p.spid , s.serial# serial_num,
nvl(s.username, ‘[Oracle process]‘) user_name, s.terminal terminal,
s.program program, st.value criteria_value from v$sesstat st, v$session s , v$process p
where st.sid = s.sid and st.statistic# = to_number(‘38‘) and (‘ALL‘ = ‘ALL‘
or s.status = ‘ALL‘) and p.addr = s.paddr order by st.value desc, p.spid asc, s.username asc, s.osuser asc

16.查看锁（lock）情况
select /*+ RULE */ ls.osuser os_user_name, ls.username user_name,
decode(ls.type, ‘RW‘, ‘Row wait enqueue lock‘, ‘TM‘, ‘DML enqueue lock‘, ‘TX‘,
‘Transaction enqueue lock‘, ‘UL‘, ‘User supplied lock‘) lock_type,
o.object_name object, decode(ls.lmode, 1, null, 2, ‘Row Share‘, 3,
‘Row Exclusive‘, 4, ‘Share‘, 5, ‘Share Row Exclusive‘, 6, ‘Exclusive‘, null)
lock_mode, o.owner, ls.sid, ls.serial# serial_num, ls.id1, ls.id2
from sys.dba_objects o, ( select s.osuser, s.username, l.type,
l.lmode, s.sid, s.serial#, l.id1, l.id2 from v$session s,
v$lock l where s.sid = l.sid ) ls where o.object_id = ls.id1 and o.owner
<> ‘SYS‘ order by o.owner, o.object_name

17.查看等待（wait）情况
SELECT v$waitstat.class, v$waitstat.count count, SUM(v$sysstat.value) sum_value
FROM v$waitstat, v$sysstat WHERE v$sysstat.name IN (‘db block gets‘,
‘consistent gets‘) group by v$waitstat.class, v$waitstat.count

18.查看sga情况
SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC

19.查看catched object
SELECT owner, name, db_link, namespace,
type, sharable_mem, loads, executions,
locks, pins, kept FROM v$db_object_cache

20.查看V$SQLAREA
SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS,
VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS,
USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,
BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA

21.查看object分类数量
select decode (o.type#,1,‘INDEX‘ , 2,‘TABLE‘ , 3 , ‘CLUSTER‘ , 4, ‘VIEW‘ , 5 ,
‘SYNONYM‘ , 6 , ‘SEQUENCE‘ , ‘OTHER‘ ) object_type , count(*) quantity from
sys.obj$ o where o.type# > 1 group by decode (o.type#,1,‘INDEX‘ , 2,‘TABLE‘ , 3
, ‘CLUSTER‘ , 4, ‘VIEW‘ , 5 , ‘SYNONYM‘ , 6 , ‘SEQUENCE‘ , ‘OTHER‘ ) union select
‘COLUMN‘ , count(*) from sys.col$ union select ‘DB LINK‘ , count(*) from

22。按用户查看object种类
select u.name schema, sum(decode(o.type#, 1, 1, NULL)) indexes,
sum(decode(o.type#, 2, 1, NULL)) tables, sum(decode(o.type#, 3, 1, NULL))
clusters, sum(decode(o.type#, 4, 1, NULL)) views, sum(decode(o.type#, 5, 1,
NULL)) synonyms, sum(decode(o.type#, 6, 1, NULL)) sequences,
sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1))
others from sys.obj$ o, sys.user$ u where o.type# >= 1 and u.user# =
o.owner# and u.name <> ‘PUBLIC‘ group by u.name order by
sys.link$ union select ‘CONSTRAINT‘ , count(*) from sys.con$

23.有关connection的相关信息
1）查看有哪些用户连接
select s.osuser os_user_name, decode(sign(48 - command), 1, to_char(command),
‘Action Code #‘ || to_char(command) ) action, p.program oracle_process,
status session_status, s.terminal terminal, s.program program,
s.username user_name, s.fixed_table_sequence activity_meter, ‘‘ query,
0 memory, 0 max_memory, 0 cpu_usage, s.sid, s.serial# serial_num
from v$session s, v$process p where s.paddr=p.addr and s.type = ‘USER‘
order by s.username, s.osuser

2）根据v.sid查看对应连接的资源占用等情况
select n.name,
v.value,
n.class,
n.statistic#
from v$statname n,
v$sesstat v
where v.sid = 71 and
v.statistic# = n.statistic#
order by n.class, n.statistic#

3）根据sid查看对应连接正在运行的sql
select /*+ PUSH_SUBQ */
command_type,
sql_text,
sharable_mem,
persistent_mem,
runtime_mem,
sorts,
version_count,
loaded_versions,
open_versions,
users_opening,
executions,
users_executing,
loads,
first_load_time,
invalidations,
parse_calls,
disk_reads,
buffer_gets,
rows_processed,
sysdate start_time,
sysdate finish_time,
‘>‘ || address sql_address,
‘N‘ status
from v$sqlarea
where address = (select sql_address from v$session where sid = 71)

24．查询表空间使用情况
select a.tablespace_name "表空间名称",
100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)",
round(a.bytes_alloc/1024/1024,2) "容量(M)",
round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)",
round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",
Largest "最大扩展段(M)",
to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss‘) "采样时间"
from (select f.tablespace_name,
sum(f.bytes) bytes_alloc,
sum(decode(f.autoextensible,‘YES‘,f.maxbytes,‘NO‘,f.bytes)) maxbytes
from dba_data_files f
group by tablespace_name) a,
(select f.tablespace_name,
sum(f.bytes) bytes_free
from dba_free_space f
group by tablespace_name) b,
(select round(max(ff.length)*16/1024,2) Largest,
ts.name tablespace_name
from sys.fet$ ff, sys.file$ tf,sys.ts$ ts
where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts#
group by ts.name, tf.blocks) c
where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name;

25. 查询表空间的碎片程度

select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name
having count(tablespace_name)>10;

alter tablespace name coalesce;
alter table name deallocate unused;

create or replace view ts_blocks_v as
select tablespace_name,block_id,bytes,blocks,‘free space‘ segment_name from dba_free_space
union all
select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents;

select * from ts_blocks_v;

select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space
group by tablespace_name;


26.监控索引是否使用
alter index &index_name monitoring usage; --开始监控
alter index &index_name nomonitoring usage; --取消监控
select * from v$object_usage where index_name = &index_name;

27.求数据文件的I/O分布
select df.name,phyrds,phywrts,phyblkrd,phyblkwrt,singleblkrds,readtim,writetim
from v$filestat fs,v$dbfile df
where fs.file#=df.file# order by df.name;

28.求某个隐藏参数的值
col ksppinm format a54
col ksppstvl format a54
select ksppinm, ksppstvl
from x$ksppi pi, x$ksppcv cv
where cv.indx=pi.indx and pi.ksppinm like ‘\_%‘ escape ‘\‘ and pi.ksppinm like ‘%&parameer%‘;

29.求系统中较大的latch
select name,sum(gets),sum(misses),sum(sleeps),sum(wait_time)
from v$latch_children
group by name having sum(gets) > 50 order by 2;

30.求归档日志的切换频率(生产系统可能时间会很长)
select start_recid,start_time,end_recid,end_time,minutes from (select test.*, rownum as rn
from (select b.recid start_recid,to_char(b.first_time,‘yyyy-mm-dd hh24:mi:ss‘) start_time,
a.recid end_recid,to_char(a.first_time,‘yyyy-mm-dd hh24:mi:ss‘) end_time,round(((a.first_time-b.first_time)*24)*60,2) minutes
from v$log_history a,v$log_history b where a.recid=b.recid+1 and b.first_time
> sysdate-{指定一个值} order by a.first_time desc) test) y where y.rn < 30

31.求回滚段正在处理的事务
select a.name,b.xacts,c.sid,c.serial#,d.sql_text
from v$rollname a,v$rollstat b,v$session c,v$sqltext d,v$transaction e
where a.usn=b.usn and b.usn=e.xidusn and c.taddr=e.addr
and c.sql_address=d.address and c.sql_hash_value=d.hash_value order by a.name,c.sid,d.piece;

32.求出无效的对象
select ‘alter procedure ‘||object_name||‘ compile;‘
from dba_objects
where status=‘INVALID‘ and owner=‘&‘ and object_type in (‘PACKAGE‘,‘PACKAGE BODY‘);
/
select owner,object_name,object_type,status from dba_objects where status=‘INVALID‘;

--求process/session的状态
select p.pid,p.spid,s.program,s.sid,s.serial#
from v$process p,v$session s where s.paddr=p.addr;

--求当前session的状态
select sn.name,ms.value
from v$mystat ms,v$statname sn
where ms.statistic#=sn.statistic# and ms.value > 0;

--求表的索引信息
select ui.table_name,ui.index_name
from user_indexes ui,user_ind_columns uic
where ui.table_name=uic.table_name and ui.index_name=uic.index_name
and ui.table_name like ‘&table_name%‘ and uic.column_name=‘&column_name‘;

--显示表的外键信息
col search_condition format a54
select table_name,constraint_name
from user_constraints
where constraint_type =‘R‘ and constraint_name in (select constraint_name from user_cons_columns where column_name=‘&1‘);
select rpad(child.table_name,25,‘ ‘) child_tablename,
rpad(cp.column_name,17,‘ ‘) referring_column,rpad(parent.table_name,25,‘ ‘) parent_tablename,
rpad(pc.column_name,15,‘ ‘) referred_column,rpad(child.constraint_name,25,‘ ‘) constraint_name
from user_constraints child,user_constraints parent,
user_cons_columns cp,user_cons_columns pc
where child.constraint_type = ‘R‘ and child.r_constraint_name = parent.constraint_name and
child.constraint_name = cp.constraint_name and parent.constraint_name = pc.constraint_name and
cp.position = pc.position and child.table_name =‘&table_name‘
order by child.owner,child.table_name,child.constraint_name,cp.position;

--显示表的分区及子分区(user_tab_subpartitions)
col table_name format a16
col partition_name format a16
col high_value format a81
select table_name,partition_name,HIGH_VALUE from user_tab_partitions where table_name=‘&table_name‘

--使用dbms_xplan生成一个执行计划
explain plan set statement_id = ‘&sql_id‘ for &sql;
select * from table(dbms_xplan.display);

--求某个事务的重做信息(bytes)
select s.name,m.value
from v$mystat m,v$statname s
where m.statistic#=s.statistic# and s.name like ‘%redo size%‘;

--求cache中缓存超过其5%的对象
select o.owner,o.object_type,o.object_name,count(b.objd)
from v$bh b,dba_objects o
where b.objd = o.object_id
group by o.owner,o.object_type,o.object_name
having count(b.objd) > (select to_number(value)*0.05 from v$parameter where name = ‘db_block_buffers‘);

--求谁阻塞了某个session(10g)
select sid, username, event, blocking_session,
seconds_in_wait, wait_time
from v$session where state in (‘WAITING‘) and wait_class != ‘Idle‘;

--求session的OS进程ID
col program format a54
select p.spid "OS Thread", b.name "Name-User", s.program
from v$process p, v$session s, v$bgprocess b
where p.addr = s.paddr and p.addr = b.paddr
UNION ALL
select p.spid "OS Thread", s.username "Name-User", s.program
from v$process p, v$session s where p.addr = s.paddr and s.username is not null;

--查会话的阻塞
col user_name format a32
select /*+ rule */ lpad(‘ ‘,decode(l.xidusn ,0,3,0))||l.oracle_username user_name, o.owner,o.object_name,s.sid,s.serial#
from v$locked_object l,dba_objects o,v$session s
where l.object_id=o.object_id and l.session_id=s.sid order by o.object_id,xidusn desc ;
col username format a15
col lock_level format a8
col owner format a18
col object_name format a32
select /*+ rule */ s.username, decode(l.type,‘tm‘,‘table lock‘, ‘tx‘,‘row lock‘, null) lock_level, o.owner,o.object_name,s.sid,s.serial#
from v$session s,v$lock l,dba_objects o
where l.sid = s.sid and l.id1 = o.object_id(+) and s.username is not null ;

--求等待的事件及会话信息/求会话的等待及会话信息
select se.sid,s.username,se.event,se.total_waits,se.time_waited,se.average_wait
from v$session s,v$session_event se
where s.username is not null and se.sid=s.sid and s.status=‘ACTIVE‘ and se.event not like ‘%SQL*Net%‘ order by s.username;
select s.sid,s.username,sw.event,sw.wait_time,sw.state,sw.seconds_in_wait
from v$session s,v$session_wait sw
where s.username is not null and sw.sid=s.sid and sw.event not like ‘%SQL*Net%‘ order by s.username;

--求会话等待的file_id/block_id
col event format a24
col p1text format a12
col p2text format a12
col p3text format a12
select sid,event,p1text, p1, p2text, p2, p3text, p3
from v$session_wait
where event not like ‘%SQL%‘ and event not like ‘%rdbms%‘ and event not like ‘%mon%‘ order by event;
select name,wait_time from v$latch l where exists (select 1 from (select sid,event,p1text, p1, p2text, p2, p3text, p3
from v$session_wait
where event not like ‘%SQL%‘ and event not like ‘%rdbms%‘ and event not like ‘%mon%‘
) x where x.p1= l.latch#);

--求会话等待的对象
col owner format a18
col segment_name format a32
col segment_type format a32
select owner,segment_name,segment_type
from dba_extents
where file_id = &file_id and &block_id between block_id and block_id + blocks - 1;

--求buffer cache中的块信息
select o.OBJECT_TYPE, substr(o.OBJECT_NAME,1,10) objname , b.objd , b.status, count(b.objd)
from v$bh b, dba_objects o
where b.objd = o.data_object_id and o.owner = ‘&1‘ group by o.object_type, o.object_name,b.objd, b.status ;

--求日志文件的空间使用
select le.leseq current_log_sequence#, 100*cp.cpodr_bno/le.lesiz percentage_full
from x$kcccp cp,x$kccle le
where le.leseq =cp.cpodr_seq;

--求等待中的对象
　select /*+rule */ s.sid, s.username, w.event, o.owner, o.segment_name, o.segment_type,
o.partition_name, w.seconds_in_wait seconds, w.state
from v$session_wait w, v$session s, dba_extents o
where w.event in (select name from v$event_name where parameter1 = ‘file#‘
and parameter2 = ‘block#‘ and name not like ‘control%‘)
and o.owner <> ‘sys‘ and w.sid = s.sid and w.p1 = o.file_id and w.p2 >= o.block_id and w.p2 < o.block_id + o.blocks

--求当前事务的重做尺寸
select value
from v$mystat, v$statname
where v$mystat.statistic# = v$statname.statistic# and v$statname.name = ‘redo size‘;

--唤醒smon去清除临时段
column pid new_value Smon
set termout off
select p.pid from sys.v_$bgprocess b,sys.v_$process p where b.name = ‘SMON‘ and p.addr = b.paddr
/
set termout on
oradebug wakeup &Smon
undefine Smon

--求回退率
select b.value/(a.value + b.value),a.value,b.value from v$sysstat a,v$sysstat b
where a.statistic#=4 and b.statistic#=5;

--求DISK READ较多的SQL
select st.sql_text from v$sql s,v$sqltext st
where s.address=st.address and s.hash_value=st.hash_value and s.disk_reads > 300;

--求DISK SORT严重的SQL
select sess.username, sql.sql_text, sort1.blocks
from v$session sess, v$sqlarea sql, v$sort_usage sort1
where sess.serial# = sort1.session_num
and sort1.sqladdr = sql.address
and sort1.sqlhash = sql.hash_value and sort1.blocks > 200;

--求对象的创建代码
column column_name format a36
column sql_text format a99
select dbms_metadata.get_ddl(‘TABLE‘,‘&1‘) from dual;
select dbms_metadata.get_ddl(‘INDEX‘,‘&1‘) from dual;

--求表的索引
set linesize 131
select a.index_name,a.column_name,b.status, b.index_type
from user_ind_columns a,user_indexes b
where a.index_name=b.index_name and a.table_name=‘&1‘;

求索引中行数较多的
select index_name,blevel,num_rows,CLUSTERING_FACTOR,status from user_indexes where num_rows > 10000 and blevel > 0
select table_name,index_name,blevel,num_rows,CLUSTERING_FACTOR,status from user_indexes where status <> ‘VALID‘

--求当前会话的SID，SERIAL#
select sid, serial# from v$session where audsid = SYS_CONTEXT(‘USERENV‘,‘SESSIONID‘);

--求表空间的未用空间
col mbytes format 9999.9999
select tablespace_name,sum(bytes)/1024/1024 mbytes from dba_free_space group by tablespace_name;

--求表中定义的触发器
select table_name,index_type,index_name,uniqueness from user_indexes where table_name=‘&1‘;
select trigger_name from user_triggers where table_name=‘&1‘;

--求未定义索引的表
select table_name from user_tables where table_name not in (select table_name from user_ind_columns);

--执行常用的过程
exec print_sql(‘select count(*) from tab‘);
exec show_space2(‘table_name‘);

--求free memory
select * from v$sgastat where name=‘free memory‘;
select a.name,sum(b.value) from v$statname a,v$sesstat b where a.statistic# = b.statistic# group by a.name;
查看一下谁在使用那个可以得回滚段，或者查看一下某个可以得用户在使用回滚段，
找出领回滚段不断增长的事务，再看看如何处理它，是否可以将它commit，再不行
就看看能否kill它，等等, 查看当前正在使用的回滚段的用户信息和回滚段信息:
set linesize 121
SELECT r.name "ROLLBACK SEGMENT NAME ",l.sid "ORACLE PID",p.spid "SYSTEM PID ",s.username "ORACLE USERNAME"
FROM v$lock l, v$process p, v$rollname r, v$session s
WHERE l.sid = p.pid(+) AND s.sid=l.sid AND TRUNC(l.id1(+)/65536) = r.usn AND l.type(+) = ‘TX‘ AND l.lmode(+) = 6 ORDER BY r.name;

--查看用户的回滚段的信息
select s.username, rn.name from v$session s, v$transaction t, v$rollstat r, v$rollname rn
where s.saddr = t.ses_addr and t.xidusn = r.usn and r.usn = rn.usn

--生成执行计划
explain plan set statement_id=‘a1‘ for &1;
--查看执行计划
select lpad(‘ ‘,2*(level-1))||operation operation,options,OBJECT_NAME,position from plan_table
start with id=0 and statement_id=‘a1‘ connect by prior id=parent_id and statement_id=‘a1‘

--查看内存中存的使用
select decode(greatest(class,10),10,decode(class,1,‘Data‘,2,‘Sort‘,4,‘Header‘,to_char(class)),‘Rollback‘) "Class",
sum(decode(bitand(flag,1),1,0,1)) "Not Dirty",sum(decode(bitand(flag,1),1,1,0)) "Dirty",
sum(dirty_queue) "On Dirty",count(*) "Total"
from x$bh group by decode(greatest(class,10),10,decode(class,1,‘Data‘,2,‘Sort‘,4,‘Header‘,to_char(class)),‘Rollback‘);

-- 查看表空间状态
select tablespace_name,extent_management,segment_space_management from dba_tablespaces;
select table_name,freelists,freelist_groups from user_tables;

--查看系统请求情况
SELECT DECODE (name, ‘summed dirty write queue length‘, value)/
DECODE (name, ‘write requests‘, value) "Write Request Length"
FROM v$sysstat WHERE name IN ( ‘summed dirty queue length‘, ‘write requests‘) and value>0;

--计算data buffer 命中率
select a.value + b.value "logical_reads", c.value "phys_reads",
round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO"
from v$sysstat a, v$sysstat b, v$sysstat c
where a.statistic# = 40 and b.statistic# = 41 and c.statistic# = 42;
SELECT name, (1-(physical_reads/(db_block_gets+consistent_gets)))*100 H_RATIO FROM v$buffer_pool_statistics;

--查看内存使用情况
select least(max(b.value)/(1024*1024),sum(a.bytes)/(1024*1024)) shared_pool_used,
max(b.value)/(1024*1024) shared_pool_size,greatest(max(b.value)/(1024*1024),sum(a.bytes)/(1024*1024))-
(sum(a.bytes)/(1024*1024)) shared_pool_avail,((sum(a.bytes)/(1024*1024))/(max(b.value)/(1024*1024)))*100 avail_pool_pct
from v$sgastat a, v$parameter b where (a.pool=‘shared pool‘ and a.name not in (‘free memory‘)) and b.name=‘shared_pool_size‘;

--查看用户使用内存情况
select username, sum(sharable_mem), sum(persistent_mem), sum(runtime_mem)
from sys.v_$sqlarea a, dba_users b
where a.parsing_user_id = b.user_id group by username;

--查看对象的缓存情况
select OWNER,NAMESPACE,TYPE,NAME,SHARABLE_MEM,LOADS,EXECUTIONS,LOCKS,PINS,KEPT
from v$db_object_cache where type not in (‘NOT LOADED‘,‘NON-EXISTENT‘,‘VIEW‘,‘TABLE‘,‘SEQUENCE‘)
and executions>0 and loads>1 and kept=‘NO‘ order by owner,namespace,type,executions desc;
select type,count(*) from v$db_object_cache group by type;

--查看库缓存命中率
select namespace,gets, gethitratio*100 gethitratio,pins,pinhitratio*100 pinhitratio,RELOADS,INVALIDATIONS from v$librarycache

--查看某些用户的hash
select a.username, count(b.hash_value) total_hash,count(b.hash_value)-count(unique(b.hash_value)) same_hash,
(count(unique(b.hash_value))/count(b.hash_value))*100 u_hash_ratio
from dba_users a, v$sqlarea b where a.user_id=b.parsing_user_id group by a.username;

--查看字典命中率
select (sum(getmisses)/sum(gets)) ratio from v$rowcache;

--查看undo段的使用情况
SELECT d.segment_name,extents,optsize,shrinks,aveshrink,aveactive,d.status
FROM v$rollname n,v$rollstat s,dba_rollback_segs d
WHERE d.segment_id=n.usn(+) and d.segment_id=s.usn(+);

--无效的对象
select owner,object_type,object_name from dba_objects where status=‘INVALID‘;
select constraint_name,table_name from dba_constraints where status=‘INVALID‘;

--求出某个进程，并对它进行跟踪
select s.sid,s.serial# from v$session s,v$process p where s.paddr=p.addr and p.spid=&1;
exec dbms_system.SET_SQL_TRACE_IN_SESSION(&1,&2,true);
exec dbms_system.SET_SQL_TRACE_IN_SESSION(&1,&2,false);

--求出锁定的对象
select do.object_name,session_id,process,locked_mode
from v$locked_object lo, dba_objects do where lo.object_id=do.object_id;

--求当前session的跟踪文件
SELECT p1.value || ‘/‘ || p2.value || ‘_ora_‘ || p.spid || ‘.ora‘ filename
FROM v$process p, v$session s, v$parameter p1, v$parameter p2
WHERE p1.name = ‘user_dump_dest‘ AND p2.name = ‘instance_name‘
AND p.addr = s.paddr AND s.audsid = USERENV(‘SESSIONID‘) AND p.background is null AND instr(p.program,‘CJQ‘) = 0;

--求对象所在的文件及块号
select segment_name,header_file,header_block
from dba_segments where segment_name like ‘&1‘;

--求对象发生事务时回退段及块号
select a.segment_name,a.header_file,a.header_block
from dba_segments a,dba_rollback_segs b
where a.segment_name=b.segment_name and b.segment_id=‘&1‘

--9i的在线重定义表
/*如果在线重定义的表没有主键需要创建主键*/
exec dbms_redefinition.can_redef_table(‘cybercafe‘,‘announcement‘);
create table anno2 as select * from announcement
exec dbms_redefinition.start_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘);
exec dbms_redefinition.sync_interim_table(‘cybercafe‘,‘announcement‘,‘anno2‘);
exec dbms_redefinition.finish_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘);
drop table anno2
exec dbms_redefinition.abort_redef_table(‘cybercafe‘,‘announcement‘,‘anno2‘);

--常用的logmnr脚本(cybercafe)
exec sys.dbms_logmnr_d.build(dictionary_filename =>‘esal‘,dictionary_location =>‘/home/oracle/logmnr‘);
exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_24050.dbf‘, options=>sys.dbms_logmnr.new);
exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22912.dbf‘, options=>sys.dbms_logmnr.addfile);
exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22913.dbf‘, options=>sys.dbms_logmnr.addfile);
exec sys.dbms_logmnr.add_logfile(logfilename=>‘/home/oracle/oradata/esal/archive/1_22914.dbf‘, options=>sys.dbms_logmnr.addfile);
exec sys.dbms_logmnr.start_logmnr(dictfilename=>‘/home/oracle/logmnr/esal.ora‘);
create table logmnr2 as select * from v$logmnr_contents;

--与权限相关的字典
ALL_COL_PRIVS 表示列上的授权，用户和PUBLIC是被授予者
ALL_COL_PRIVS_MADE 表示列上的授权，用户是属主和被授予者
ALL_COL_RECD 表示列上的授权，用户和PUBLIC是被授予者
ALL_TAB_PRIVS 表示对象上的授权，用户是PUBLIC或被授予者或用户是属主
ALL_TAB_PRIVS_MADE 表示对象上的权限，用户是属主或授予者
ALL_TAB_PRIVS_RECD 表示对象上的权限, 用户是PUBLIC或被授予者
DBA_COL_PRIVS 数据库列上的所有授权
DBA_ROLE_PRIVS 显示已授予用户或其他角色的角色
DBA_SYS_PRIVS 已授予用户或角色的系统权限
DBA_TAB_PRIVS 数据库对象上的所有权限
ROLE_ROLE_PRIVS 显示已授予用户的角色
ROLE_SYS_PRIVS 显示通过角色授予用户的系统权限
ROLE_TAB_PRIVS 显示通过角色授予用户的对象权限
SESSION_PRIVS 显示用户现在可利用的所有系统权限
USER_COL_PRIVS 显示列上的权限，用户是属主、授予者或被授予者
USER_COL_PRIVS_MADE 显示列上已授予的权限，用户是属主或授予者
USER_COL_PRIVS_RECD 显示列上已授予的权限，用户是属主或被授予者
USER_ROLE_PRIVS 显示已授予给用户的所有角色
USER_SYS_PRIVS 显示已授予给用户的所有系统权限
USER_TAB_PRIVS 显示已授予给用户的所有对象权限
USER_TAB_PRIVS_MADE 显示已授予给其他用户的对象权限，用户是属主
USER_TAB_PRIVS_RECD 显示已授予给其他用户的对象权限，用户是被授予者

--如何用dbms_stats分析表及模式？
exec dbms_stats.gather_schema_stats(
ownname=>‘&USER_NAME‘,
estimate_percent=>dbms_stats.auto_sample_size,
method_opt => ‘for all columns size auto‘,
degree=> DBMS_STATS.DEFAULT_DEGREE
);

exec dbms_stats.gather_schema_stats(
ownname=>‘&USER_NAME‘,
estimate_percent=>dbms_stats.
auto_sample_size,cascade=>true
);