查看scnheadroom变化趋势的几种方法
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2024-01-18 19:49:46
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查看scn headroom变化趋势的几种方法 scn headroom问题，本文不做解释。 本文为自己的总结，脚本来自于oracle sr技术工程师。 转载请注明出处http://blog.csdn.net/msdnchina/article/details/38404501 第一个方法：查询smon_scn_time表获得。conn / as sysdb
查看scn headroom变化趋势的几种方法scn headroom问题，本文不做解释。
本文为自己的总结，脚本来自于oracle sr技术工程师。
转载请注明出处http://blog.csdn.net/msdnchina/article/details/38404501
第一个方法：查询smon_scn_time表获得。conn / as sysdbaset numwidth 17
set pages 1000
alter session set nls_date_format='DD/Mon/YYYY HH24:MI:SS';
with t1 as(
select time_dp , 24*60*60*(time_dp - lag(time_dp) over (order by time_dp)) timediff,
scn - lag(scn) over(order by time_dp) scndiff
from smon_scn_time
)
select time_dp , timediff, scndiff,
trunc(scndiff/timediff) rate_per_sec
from t1
order by 1;
第二个方法：查询awr报告的信息：
1. 通过How to extract the historical values of a statistic from AWR Repository (Doc ID 948272.1)
将Script 部分复制到您生成数据库两个实例本地，命名为 例如 awr.sql
该脚本为：
set trimspool on
set pages 50000
set lines 132
set tab off
set feedback off
clear break compute;
repfooter off;
ttitle off;
btitle off;
set timing off veri off space 1 flush on pause off termout on numwidth 10;
set echo off feedback off pagesize 50000 linesize 1000 newpage 1 recsep off;
set trimspool on trimout on;
--
-- Request the DB Id and Instance Number, if they are not specified
column instt_num heading "Inst Num" format 99999;
column instt_name heading "Instance" format a12;
column dbb_name heading "DB Name" format a12;
column dbbid heading "DB Id" format a12 just c;
column host heading "Host" format a20;
prompt
prompt
prompt instances IN this workload repository SCHEMA
prompt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SELECT DISTINCT ( CASE
WHEN cd.dbid = wr.dbid
AND cd.name = wr.db_name
AND ci.instance_number = wr.instance_number
AND ci.instance_name = wr.instance_name THEN '* '
ELSE ' '
END )
|| wr.dbid dbbid,
wr.instance_number instt_num,
wr.db_name dbb_name,
wr.instance_name inst_name,
wr.host_name host
FROM dba_hist_database_instance wr,
v$database cd,
v$instance ci;
prompt
prompt USING &&dbid FOR DATABASE id
--
-- Set up the binds for dbid and instance_number
variable dbid NUMBER;
BEGIN
:dbid := &dbid;
END;
/
-- Error reporting
whenever SQLERROR EXIT;
variable max_snap_time CHAR(10);
DECLARE
CURSOR cidnum IS
SELECT 'X'
FROM dba_hist_database_instance
WHERE dbid = :dbid;
CURSOR csnapid IS
SELECT To_char(Max(end_interval_time), 'dd/mm/yyyy')
FROM dba_hist_snapshot
WHERE dbid = :dbid;
vx CHAR(1);
BEGIN
-- Check Database Id/Instance Number is a valid pair
OPEN cidnum;
FETCH cidnum INTO vx;
IF cidnum%NOTFOUND THEN
Raise_application_error(-20200, 'Database/Instance '
|| :dbid
|| '/'
||
' does not exist in DBA_HIST_DATABASE_INSTANCE');
END IF;
CLOSE cidnum;
-- Check Snapshots exist for Database Id/Instance Number
OPEN csnapid;
FETCH csnapid INTO :max_snap_time;
IF csnapid%NOTFOUND THEN
Raise_application_error(-20200,
'No snapshots exist for Database/Instance '
||:dbid
||'/');
END IF;
CLOSE csnapid;
END;
/
whenever SQLERROR CONTINUE;
--
-- Ask how many days of snapshots to display
set termout ON;
column instart_fmt noprint;
column inst_name format a12 heading 'Instance';
column db_name format a12 heading 'DB Name';
column snap_id format 99999990 heading 'Snap Id';
column snapdat format a18 heading 'Snap Started' just c;
column lvl format 99 heading 'Snap|Level';
prompt
prompt
prompt specify the NUMBER OF days OF snapshots TO choose FROM
prompt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prompt entering the NUMBER OF days (n) will result IN the most recent
prompt (n) days OF snapshots being listed. pressing without
prompt specifying a NUMBER LISTS ALL completed snapshots.
prompt
prompt
set heading OFF;
column num_days new_value num_days noprint;
SELECT 'Listing '
|| Decode(Nvl('&&num_days', 3.14), 0, 'no snapshots',
3.14, 'all Completed Snapshots',
1,
'the last day''s Completed Snapshots',
'the last &num_days days of Completed Snapshots'
),
Nvl('&&num_days', 3.14) num_days
FROM sys.dual;
set heading ON;
--
-- List available snapshots
break ON inst_name ON db_name ON host ON instart_fmt skip 1;
ttitle OFF;
SELECT To_char(s.startup_time, 'dd Mon "at" HH24:mi:ss') instart_fmt,
di.instance_name inst_name,
di.db_name db_name,
s.snap_id snap_id,
To_char(s.end_interval_time, 'dd Mon YYYY HH24:mi') snapdat,
s.snap_level lvl
FROM dba_hist_snapshot s,
dba_hist_database_instance di
WHERE s.dbid = :dbid
AND di.dbid = :dbid
AND di.dbid = s.dbid
AND di.instance_number = s.instance_number
AND di.startup_time = s.startup_time
AND s.end_interval_time >= Decode(&num_days, 0, To_date('31-JAN-9999',
'DD-MON-YYYY'
),
3.14, s.end_interval_time,
To_date(:max_snap_time,
'dd/mm/yyyy')
- ( &num_days - 1 ))
ORDER BY db_name,
instance_name,
snap_id;
clear break;
ttitle OFF;
--
-- Ask for the snapshots Id's which are to be compared
prompt
prompt
prompt specify the BEGIN AND END SNAPSHOT ids
prompt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prompt BEGIN SNAPSHOT id specified: &&begin_snap
prompt
prompt END SNAPSHOT id specified: &&end_snap
prompt
--
-- Set up the snapshot-related binds
--
variable bid NUMBER;
variable eid NUMBER;
BEGIN
:bid := &begin_snap;
:eid := &end_snap;
END;
/
prompt
--
-- Ask for Statistics Name Filter
--
prompt
prompt
prompt search statistic
prompt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prompt search BY STATISTICS name. pressing without
prompt specifying anything show ALL STATISTICS.
set heading OFF;
column stat_search new_value stat_search noprint;
SELECT 'Statistic Name Filter: '
|| Nvl('&&stat_search', '%'),
Nvl('&&stat_search', '%') stat_search
FROM sys.dual;
set heading ON;
column stat_id heading "Statistic ID" format 9999999999999;
column name heading "Statistic Name" format a64;
column class_name heading "Statistic Class" format a10;
SELECT stat_id,
( CASE
WHEN class = 1 THEN 'USER'
WHEN class = 2 THEN 'REDO'
WHEN class = 4 THEN 'ENQUEUE'
WHEN class = 8 THEN 'CACHE'
WHEN class = 16 THEN 'OS'
WHEN class = 32 THEN 'RAC'
WHEN class = 40 THEN 'RAC-CACHE'
WHEN class = 64 THEN 'SQL'
WHEN class = 72 THEN 'SQL-CACHE'
WHEN class = 128 THEN 'DEBUG'
ELSE To_char(class)
END ) CLASS_NAME,
name
FROM v$sysstat
WHERE Upper(name) LIKE Trim(Upper('%&stat_search%'))
ORDER BY class,
name
/
--
-- Ask for the statistics
variable stat_filter_id NUMBER
variable stat_filter_name VARCHAR2(64)
prompt
prompt
prompt specify the STATISTICS
prompt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prompt enter STATISTICS id OR STATISTICS name.
prompt
BEGIN
SELECT To_number('&&stat_input')
INTO :stat_filter_id
FROM dual;
EXCEPTION
WHEN invalid_number THEN
:stat_filter_name := '&stat_input';
END;
/
prompt STATISTICS specified : &&stat_input
column end_interval_time heading 'Snap Started' format a18 just c;
column dbid heading 'DB Id' format a12 just c;
column instance_number heading 'Inst|Num' format 99999;
column elapsed heading 'Elapsed' format 999999;
column stat_value heading 'Stat Value' format 999999999999
column stat_name heading 'Stat Name' format a64 just l;
SELECT snap_id,
To_char(dbid) DBID,
instance_number,
elapsed,
To_char(end_interval_time, 'dd Mon YYYY HH24:mi') END_INTERVAL_TIME,
--stat_name,
( CASE
WHEN stat_value > 0 THEN stat_value
ELSE 0
END ) STAT_VALUE
FROM (SELECT snap_id,
dbid,
instance_number,
elapsed,
end_interval_time,
stat_name,
( stat_value - Lag (stat_value, 1, stat_value)
over (
PARTITION BY dbid, instance_number
ORDER BY snap_id) ) AS STAT_VALUE
FROM (SELECT snap_id,
dbid,
instance_number,
elapsed,
end_interval_time,
stat_name,
SUM(stat_value) AS STAT_VALUE
FROM (SELECT X.snap_id,
X.dbid,
X.instance_number,
Trunc(SN.end_interval_time, 'mi')
END_INTERVAL_TIME,
X.stat_name,
Trunc(( Cast(SN.end_interval_time AS DATE) -
Cast(SN.begin_interval_time AS DATE) ) *
86400) ELAPSED,
( CASE
WHEN ( X.stat_name = :stat_filter_name
OR X.stat_id = :stat_filter_id ) THEN
X.value
ELSE 0
END ) AS STAT_VALUE
FROM dba_hist_sysstat X,
dba_hist_snapshot SN,
(SELECT instance_number,
Min(startup_time) STARTUP_TIME
FROM dba_hist_snapshot
WHERE snap_id BETWEEN :bid AND :eid
GROUP BY instance_number) MS
WHERE X.snap_id = sn.snap_id
AND X.dbid = sn.dbid
AND x.dbid = :dbid
AND x.snap_id BETWEEN :bid AND :eid
AND SN.startup_time = MS.startup_time
AND SN.instance_number = MS.instance_number
AND X.instance_number = sn.instance_number
AND ( X.stat_name = :stat_filter_name
OR X.stat_id = :stat_filter_id ))
GROUP BY snap_id,
dbid,
instance_number,
elapsed,
end_interval_time,
stat_name));
undefine dbid
undefine num_days
undefine begin_snap
undefine end_snap
undefine stat_id
undefine stat_search
undefine stat_filter_name
undefine stat_filter_id
undefine stat_input
---该脚本结束。
2. 在SQLPLUS中运行该脚本，并根据您系统实际情况输入
instances IN this workload repository SCHEMA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DB Id Inst Num DB Name INST_NAME Host
------------ -------- ------------ ---------------- --------------------
* 1163866261 1 RBIG5 RBIG5 xxx
m
Enter value for dbid: 1163866261 《=====输入实例ID
USING 1163866261 FOR DATABASE id
specify the NUMBER OF days OF snapshots TO choose FROM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
entering the NUMBER OF days (n) will result IN the most recent
(n) days OF snapshots being listed. pressing without
specifying a NUMBER LISTS ALL completed snapshots.
Enter value for num_days: 2
set numwidth 17
set pages 1000
alter session set nls_date_format='DD/Mon/YYYY HH24:MI:SS';
SELECT tim, gscn,
round(rate),
round((chk16kscn - gscn)/24/3600/16/1024,1) "Headroom"
FROM
(
select tim, gscn, rate,
((
((to_number(to_char(tim,'YYYY'))-1988)*12*31*24*60*60) +
((to_number(to_char(tim,'MM'))-1)*31*24*60*60) +
(((to_number(to_char(tim,'DD'))-1))*24*60*60) +
(to_number(to_char(tim,'HH24'))*60*60) +
(to_number(to_char(tim,'MI'))*60) +
(to_number(to_char(tim,'SS')))
) * (16*1024)) chk16kscn
from
(
select FIRST_TIME tim , FIRST_CHANGE# gscn,
((NEXT_CHANGE#-FIRST_CHANGE#)/
((NEXT_TIME-FIRST_TIME)*24*60*60)) rate
from v$archived_log
where (next_time > first_time)
)
)
order by 1,2
;