oracle_sql.txt

1.You can find TOP Elapsed time SQL in certain hours with below script.

SELECT st.sql_text, sub.sql_id, sub.ELAPSED_TIME PER_EXEC_ELAPSED_TIME_MINUTES
FROM DBA_HIST_SQLTEXT st,
( SELECT t.sql_id,
ROUND (
SUM (t.elapsed_time_delta / 60000000)
/ SUM (t.executions_delta))
ELAPSED_TIME
FROM dba_hist_sqlstat t, dba_hist_snapshot s, DBA_HIST_SQLTEXT st
WHERE t.snap_id = s.snap_id
AND t.dbid = s.dbid
AND t.instance_number = s.instance_number
AND t.executions_delta > 0
AND s.BEGIN_INTERVAL_TIME >
TO_DATE ('11/15/2018 13:00:00',
'mm/dd/yyyy hh24:mi:ss')
AND END_INTERVAL_TIME <
TO_DATE ('11/15/2018 16:01:00',
'mm/dd/yyyy hh24:mi:ss')
GROUP BY t.sql_id
ORDER BY 2 DESC) sub
WHERE sub.sql_id = st.sql_id
ORDER BY 3 DESC;

2.You can find TOP CPU SQL for last 24 hours with following script.

select * from (
select ss.sql_text,
    a.SQL_ID, 
    sum(CPU_TIME_DELTA), 
    sum(DISK_READS_DELTA),
    count(*)
from 
    DBA_HIST_SQLSTAT a, dba_hist_snapshot s,v$sql ss
where
 s.snap_id = a.snap_id and a.sql_id=ss.sql_id
 and s.begin_interval_time > sysdate -1
    group by 
    ss.sql_text,a.SQL_ID
order by 
    sum(CPU_TIME_DELTA) desc)
where rownum<20;

3. You can find TOP IO SQL for last 24 hours with following script.
select * from 
(
SELECT /*+LEADING(x h) USE_NL(h)*/ 
       h.sql_id
,      SUM(10) ash_secs
FROM   dba_hist_snapshot x
,      dba_hist_active_sess_history h
WHERE   x.begin_interval_time > sysdate -1
AND    h.SNAP_id = X.SNAP_id
AND    h.dbid = x.dbid
AND    h.instance_number = x.instance_number
AND    h.event in  ('db file sequential read','db file scattered read')
GROUP BY h.sql_id
ORDER BY ash_secs desc )
where rownum<10;

4. You can find TOP 10 SQL for last 1 hour with following script.
select * from (
select active_session_history.sql_id,
 dba_users.username,
 sqlarea.sql_text,
sum(active_session_history.wait_time +
active_session_history.time_waited) ttl_wait_time
from v$active_session_history active_session_history,
v$sqlarea sqlarea,
 dba_users
where 
active_session_history.sample_time between sysdate -  1/24  and sysdate
  and active_session_history.sql_id = sqlarea.sql_id
and active_session_history.user_id = dba_users.user_id
 group by active_session_history.sql_id,sqlarea.sql_text, dba_users.username
 order by 4 desc )
where rownum <11;


5. You can find TOP 10 SQL for last 1 hour with following script.
select * from (
select active_session_history.sql_id,
 dba_users.username,
 sqlarea.sql_text,
sum(active_session_history.wait_time +
active_session_history.time_waited) ttl_wait_time
from v$active_session_history active_session_history,
v$sqlarea sqlarea,
 dba_users
where 
active_session_history.sample_time between sysdate -  1/24  and sysdate
  and active_session_history.sql_id = sqlarea.sql_id
and active_session_history.user_id = dba_users.user_id
 group by active_session_history.sql_id,sqlarea.sql_text, dba_users.username
 order by 4 desc )
where rownum <11;

You can check Top Oracle database wait events in Cache which is v$ queries with below script.

select  wait_class,
       sum(total_waits), sum(time_waited)
    from gv$session_wait_class
    where wait_class !='Idle'
    group by wait_class
    order by 3 desc;


You can check Top Oracle database wait events from Active session history which is v$active_session_history queries with below script.

select * from (
select active_session_history.event,
sum(active_session_history.wait_time +
active_session_history.time_waited) ttl_wait_time
from gv$active_session_history active_session_history
where active_session_history.event is not null
group by active_session_history.event
order by 2 desc)
where rownum <= 10;

You can check Top Oracle database wait events at specific intervals. You should type date and SNAP_ID

select snap_id,begin_interval_time,end_interval_time
from dba_hist_snapshot
where to_char(begin_interval_time,'DD-MON-YYYY')='20-FEB-2019'
and EXTRACT(HOUR FROM begin_interval_time) between 8 and 10;

select * from (
select active_session_history.event,
sum(active_session_history.wait_time +
active_session_history.time_waited) ttl_wait_time
from dba_hist_active_sess_history active_session_history
where event is not null
and SNAP_ID between 34411 and 34431
group by active_session_history.event
order by 2 desc)
where rownum<10;

To find any SQL’s SQL_ID and other SQL informations in the cache, use following SQL. Following query will find if related SQL exists in the cache, if not exists it will not find.

select * from gv$sql where sql_text like '%DEVECI%';
 

To search any SQL historical in Oracle database you may use following SQL. Just change begin Interval time column and SQL_TEXT column.

 

SELECT STAT.SQL_ID, SQL_TEXT, PLAN_HASH_VALUE, PARSING_SCHEMA_NAME, ELAPSED_TIME_DELTA, 
STAT.SNAP_ID, SS.END_INTERVAL_TIME, EXECUTIONS_DELTA FROM DBA_HIST_SQLSTAT STAT, 
DBA_HIST_SQLTEXT TXT, DBA_HIST_SNAPSHOT SS WHERE STAT.SQL_ID = TXT.SQL_ID AND
STAT.DBID = TXT.DBID AND SS.DBID = STAT.DBID AND SS.INSTANCE_NUMBER = STAT.INSTANCE_NUMBER 
AND STAT.SNAP_ID = SS.SNAP_ID AND
SS.BEGIN_INTERVAL_TIME >= sysdate-31 AND
UPPER(SQL_TEXT) LIKE '%DEVECI%' ORDER BY ELAPSED_TIME_DELTA DESC;



You can find average Active session of database with following script.

 

SELECT 'Load',
CASE
WHEN ( ( CAST (end_time.sample_time AS DATE)
- CAST (start_time.sample_time AS DATE))
* 24
* 60
* 60) = 0
THEN
0
ELSE
ROUND (
( COUNT (ash.sample_id)
/ ( ( CAST (end_time.sample_time AS DATE)
- CAST (start_time.sample_time AS DATE))
* 24
* 60
* 60)),
2)
END
AS Average_Active_Session
FROM (SELECT MIN (sample_time) sample_time
FROM v$active_session_history ash
WHERE sample_time BETWEEN SYSDATE - 1 / 1440 AND SYSDATE) start_time,
(SELECT MAX (sample_time) sample_time
FROM gv$active_session_history
WHERE sample_time BETWEEN SYSDATE - 1 / 1440 AND SYSDATE) end_time,
gv$active_session_history ash
WHERE ash.sample_time BETWEEN start_time.sample_time
AND end_time.sample_time
GROUP BY end_time.sample_time, start_time.sample_time;

To list all User Sessions not Background, use following scripts. This script will list you just only User type sessions and their detais.

select * FROM gv$session s, gv$process p
WHERE s.paddr = p.addr(+)
and s.TYPE ='USER' and s.username!='SYS';
 

You can list how many Active and Inactive User sessions are in the Oracle database with following script.

select count(*) FROM gv$session s, gv$process p
WHERE s.paddr = p.addr(+)
and s.TYPE ='USER' and s.username!='SYS';


You can list only Active User sessions without sys user with following script

select count(*) FROM gv$session s, gv$process p
WHERE s.paddr = p.addr(+)
and s.TYPE ='USER' and s.username!='SYS' and status='ACTIVE';
 

You can list only Inactive User sessions without sys user with following script

select count(*) FROM gv$session s, gv$process p
WHERE s.paddr = p.addr(+)
and s.TYPE ='USER' and s.username!='SYS' and status='INACTIVE';

You can list all user sessions which are ACTIVE state more than 600 Second with following script.

select count(*) FROM gv$session s, gv$process p
WHERE s.paddr = p.addr(+)
and s.TYPE ='USER' and s.username!='SYS' and status='ACTIVE' and last_call_et > 600

You can find out all queries which are not using bind variables with following script. You can see more queries with changing row nums of script.

 

Select * 
from (
With subs as
(SELECT /*+ materialize */
m.sql_id, k.*, m.SQL_TEXT, m.SQL_FULLTEXT
FROM (SELECT inst_id,
parsing_schema_name AS user_name,
module,
plan_hash_value,
COUNT(0) copies,
SUM(executions) executions,
SUM(round(sharable_mem / (1024 * 1024), 2)) sharable_mem_mb
FROM gv$sqlarea
WHERE executions < 5
AND kept_versions = 0
GROUP BY inst_id, parsing_schema_name, module, plan_hash_value
HAVING COUNT(0) > 10
ORDER BY COUNT(0) DESC) k
LEFT JOIN gv$sqlarea m
ON k.plan_hash_value = m.plan_hash_value
WHERE k.plan_hash_value > 0)
select distinct ki.inst_id,
t.sql_id,
ki.sql_text,
t.plsql_procedure,
ki.user_name,
sum(ki.copies) copies,
sum(ki.executions) executions,
sum(ki.sharable_mem_mb) sharable_mem_mb
from (select sql_id,
program_id,
program_line#,
action,
module,
service,
parsing_schema_name,
round(buffer_gets / decode(executions, 0, 1, executions)) buffer_per_Exec,
row_number() over(partition by sql_id order by program_id desc, program_line#) sira,
decode(program_id,
0,
null,
owner || '.' || object_name || '(' || program_line# || ')') plsql_procedure
from gv$sql a, dba_objects b
where a.program_id = b.object_id(+)) t,
subs ki
where ki.sql_id = t.sql_id
and t.sira = 1
group by ki.inst_id,
t.sql_id,
ki.sql_text,
t.plsql_procedure,
ki.user_name
order by sum(ki.executions) desc
)
where rownum < 51; 

You will find object detail of queries which is not using bind variables.
With subs as
(SELECT /*+ materialize */
   m.sql_id, k.*, m.SQL_TEXT, m.SQL_FULLTEXT
    FROM (SELECT inst_id,
                 parsing_schema_name AS user_name,
                 module,
                 plan_hash_value,
                 COUNT(0) copies,
                 SUM(executions) executions,
                 SUM(round(sharable_mem / (1024 * 1024), 2)) sharable_mem_mb
            FROM gv$sqlarea
           WHERE executions < 5
             AND kept_versions = 0
           GROUP BY inst_id, parsing_schema_name, module, plan_hash_value
          HAVING COUNT(0) > 10
           ORDER BY COUNT(0) DESC) k
    LEFT JOIN gv$sqlarea m
      ON k.plan_hash_value = m.plan_hash_value
   WHERE k.plan_hash_value > 0)
select *
  from (select sql_id,
               program_id,
               program_line#,
               action,
               module,
               service,
               parsing_schema_name,
               round(buffer_gets / decode(executions, 0, 1, executions)) buffer_per_Exec,
               row_number() over(partition by sql_id order by program_id desc, program_line#) lines,
               decode(program_id,
                      0,
                      null,
                      owner || '.' || object_name || '(' || program_line# || ')') plsql_procedure
          from gv$sql a, dba_objects b
         where a.program_id = b.object_id(+)) t,
       subs ki
where ki.sql_id = t.sql_id
   and lines = 1;
   
 


1.监控索引是否使用

alter index &index_name monitoring usage;

alter index &index_name nomonitoring usage;

select * from v$object_usage where index_name = &index_name;

 

2.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;           

 

3.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 '%meer%';

 

4.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;

 

5.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 - 1

order by a.first_time desc) test) y where y.rn < 30

 

6.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;

 

7.求出无效的对象

select 'alter procedure '||object_name||' compile;'

from dba_objects

where status='INVALID' and wner='&' and object_type in ('PACKAGE','PACKAGE BODY');

/

select owner,object_name,object_type,status from dba_objects where status='INVALID';

 

8.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;

 

9.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;

 

10.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';

 

11.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;

 

12.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'

 

13.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%';

 

14.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');

 

15.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';

 

16.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;

 

17.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 ;

 

18.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;

 

19.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#);

 

20.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;                   

 

21.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 ;

 

22.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;

 

23.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

 

24.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';

                                                                                                                                                           

25.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

 

26.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;

 

28.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;

 

29.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;

 

30.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'

 

31.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;

 

32.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';

 

33.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);

 

34.执行常用的过程

exec print_sql('select count(*) from tab');

exec show_space2('table_name');

 

35.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;

 

36.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

 

37.生成执行计划

explain plan set statement_id='a1' for &1;

 

38.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'

执行计划
1）根据SID，从v$sql中找到相应SQL的HASH_VALUE和ADDRESS ；
Alan Lee(160921) 22:58:07
2）根据hash_value和address的值，从v$sql_plan中找到真实的执行计划。
这2步，就可以找出实际正在跑的SQL使用的是什么执行计划

set autotrace traceonly statistics
set autotrace traceonly explain
set autotrace traceonly on explain

 

39.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');

 

40.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;

 

41.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;

 

42.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;

 

43.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';

 

44.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;

 

45.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;

 

46.查看库缓存命中率

select namespace,gets, gethitratio*100 gethitratio,pins,pinhitratio*100 pinhitratio,RELOADS,INVALIDATIONS from v$librarycache

 

47.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;

 

48.查看字典命中率

select (sum(getmisses)/sum(gets)) ratio from v$rowcache;

 

49.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(+);

 

50.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';

 

51.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);

 

 

52.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;

 

53.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;

 

54.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';

 

55.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'

 

56.9i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');

 

57.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', ptions=>sys.dbms_logmnr.new);

exec sys.dbms_logmnr.add_logfile(logfilename=>'/home/oracle/oradata/esal/archive/1_22912.dbf', ptions=>sys.dbms_logmnr.addfile);

exec sys.dbms_logmnr.add_logfile(logfilename=>'/home/oracle/oradata/esal/archive/1_22913.dbf', ptions=>sys.dbms_logmnr.addfile);

exec sys.dbms_logmnr.add_logfile(logfilename=>'/home/oracle/oradata/esal/archive/1_22914.dbf', ptions=>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;