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Oracle 11g Adaptive Cursor Sharing (ACS)

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标签:

unstable_plans.sql – this one shows statements that have multiple plans with large variance in execution time
awr_plan_change.sql – history of how the statement plan changes over time
awr_plan_stats.sql – aggregate statement stats (like elapsed_time, lio, etc) grouped by plan
find_sql_acs.sql – A queries v$sql and shows ACS related columns
mismatch3.sql – A variation of Dion Cho’s script to display data from v$sql_shared_cursor (see his post here) 
----------------------------------------------------------------------------------------
--
-- File name:   unstable_plans.sql
--
-- Purpose:     Attempts to find SQL statements with plan instability.
--
-- Author:      Kerry Osborne
--
-- Usage:       This scripts prompts for two values, both of which can be left blank.
--
--              min_stddev: the minimum "normalized" standard deviation between plans 
--                          (the default is 2)
--
--              min_etime:  only include statements that have an avg. etime > this value
--                          (the default is .1 second)
--
-- See http://kerryosborne.oracle-guy.com/2008/10/unstable-plans/ for more info.
---------------------------------------------------------------------------------------

set lines 155
col execs for 999,999,999
col min_etime for 999,999.99
col max_etime for 999,999.99
col avg_etime for 999,999.999
col avg_lio for 999,999,999.9
col norm_stddev for 999,999.9999
col begin_interval_time for a30
col node for 99999
break on plan_hash_value on startup_time skip 1
select * from (
select sql_id, sum(execs), min(avg_etime) min_etime, max(avg_etime) max_etime, stddev_etime/min(avg_etime) norm_stddev
from (
select sql_id, plan_hash_value, execs, avg_etime,
stddev(avg_etime) over (partition by sql_id) stddev_etime
from (
select sql_id, plan_hash_value,
sum(nvl(executions_delta,0)) execs,
(sum(elapsed_time_delta)/decode(sum(nvl(executions_delta,0)),0,1,sum(executions_delta))/1000000) avg_etime
-- sum((buffer_gets_delta/decode(nvl(buffer_gets_delta,0),0,1,executions_delta))) avg_lio
from DBA_HIST_SQLSTAT S, DBA_HIST_SNAPSHOT SS
where ss.snap_id = S.snap_id
and ss.instance_number = S.instance_number
and executions_delta > 0
group by sql_id, plan_hash_value
)
)
group by sql_id, stddev_etime
)
where norm_stddev > nvl(to_number(&min_stddev),2)
and max_etime > nvl(to_number(&min_etime),.1)
order by norm_stddev
/
----------------------------------------------------------------------------------------
--
-- File name:   awr_plan_change.sql
--
---------------------------------------------------------------------------------------

set lines 155
col execs for 999,999,999
col avg_etime for 999,999.999
col avg_lio for 999,999,999.9
col begin_interval_time for a30
col node for 99999
break on plan_hash_value on startup_time skip 1
select ss.snap_id, ss.instance_number node, begin_interval_time, sql_id, plan_hash_value,
nvl(executions_delta,0) execs,
(elapsed_time_delta/decode(nvl(executions_delta,0),0,1,executions_delta))/1000000 avg_etime,
(buffer_gets_delta/decode(nvl(buffer_gets_delta,0),0,1,executions_delta)) avg_lio
from DBA_HIST_SQLSTAT S, DBA_HIST_SNAPSHOT SS
where sql_id = nvl(&sql_id,4dqs2k5tynk61)
and ss.snap_id = S.snap_id
and ss.instance_number = S.instance_number
and executions_delta > 0
order by 1, 2, 3
/
----------------------------------------------------------------------------------------
--
-- File name:   awr_plan_stats.sql
--
---------------------------------------------------------------------------------------
-- Note that I have modified this script slightly to include snaps with 0 executions.
-- This is to account for situations with very long running statements (that generally
-- cross snapshot boundaries). In these situations, the executions_delta is incremented 
-- in the snapshot when the statement begins. There will be 0 executions_delta in
-- subsequent snapshots, but the time and lio‘s should still be considered.
set lines 155
col execs for 999,999,999
col etime for 999,999,999.9
col avg_etime for 999,999.999
col avg_cpu_time for 999,999.999
col avg_lio for 999,999,999.9
col avg_pio for 9,999,999.9
col begin_interval_time for a30
col node for 99999
break on plan_hash_value on startup_time skip 1
select sql_id, plan_hash_value, 
sum(execs) execs, 
-- sum(etime) etime, 
sum(etime)/sum(execs) avg_etime, 
sum(cpu_time)/sum(execs) avg_cpu_time,
sum(lio)/sum(execs) avg_lio, 
sum(pio)/sum(execs) avg_pio
from (
select ss.snap_id, ss.instance_number node, begin_interval_time, sql_id, plan_hash_value,
nvl(executions_delta,0) execs,
elapsed_time_delta/1000000 etime,
(elapsed_time_delta/decode(nvl(executions_delta,0),0,1,executions_delta))/1000000 avg_etime,
buffer_gets_delta lio,
disk_reads_delta pio,
cpu_time_delta/1000000 cpu_time,
(buffer_gets_delta/decode(nvl(buffer_gets_delta,0),0,1,executions_delta)) avg_lio,
(cpu_time_delta/decode(nvl(executions_delta,0),0,1,executions_delta)) avg_cpu_time
from DBA_HIST_SQLSTAT S, DBA_HIST_SNAPSHOT SS
where sql_id = nvl(&sql_id,4dqs2k5tynk61)
and ss.snap_id = S.snap_id
and ss.instance_number = S.instance_number 
-- and executions_delta > 0
)
group by sql_id, plan_hash_value
order by 5
/
----------------------------------------------------------------------------------------
--
-- File name:   find_sql_acs.sql
--
---------------------------------------------------------------------------------------

set verify off
set pagesize 999
col username format a13
col prog format a22
col sql_text format a35
col sid format 999
col child_number format 99999 heading CHILD
col ocategory format a10
col execs format 9,999,999
col execs_per_sec format 999,999.99
col etime format 9,999,999.99
col avg_etime format 99,999.99
col cpu format 9,999,999
col avg_cpu  format 99,999.99
col pio format 9,999,999
col avg_pio format 99,999.99
col lio format 9,999,999
col avg_lio format 9,999,999
col ibs format a3
col iba format a3
col ish format a3

select sql_id, child_number, plan_hash_value,
is_bind_sensitive ibs,
is_bind_aware iba,
is_shareable ish,
executions execs,
rows_processed ,
-- executions/((sysdate-to_date(first_load_time,‘YYYY-MM-DD/HH24:MI:SS‘))*(24*60*60)) execs_per_sec,
-- elapsed_time/1000000 etime,
(elapsed_time/1000000)/decode(nvl(executions,0),0,1,executions) avg_etime,
-- cpu_time/1000000 cpu,
(cpu_time/1000000)/decode(nvl(executions,0),0,1,executions) avg_cpu,
-- disk_reads pio,
disk_reads/decode(nvl(executions,0),0,1,executions) avg_pio,
-- buffer_gets lio,
buffer_gets/decode(nvl(executions,0),0,1,executions) avg_lio,
sql_text
from v$sql s
where sql_text like nvl(&sql_text,sql_text)
and sql_text not like %from v$sql where sql_text like nvl(%
and sql_id like nvl(&sql_id,sql_id)
and is_bind_aware like nvl(&is_bind_aware,is_bind_aware)
order by sql_id, child_number
/
----------------------------------------------------------------------------------------
--
-- File name:   mismatch3.sql
--
---------------------------------------------------------------------------------------
-- Modified version of Dion Cho‘s script - http://dioncho.wordpress.com/?s=v%24sql_shared_cursor
--
-- Modified by Kerry Osborne
-- I just changed the output columns (got rid of sql_text and address columns and added last_load_time)
-- I also ordered the output by last_load_time.
-- 
declare
  c         number;
  col_cnt   number;
  col_rec   dbms_sql.desc_tab;
  col_value varchar2(4000);
  ret_val    number;
begin
  c := dbms_sql.open_cursor;
  dbms_sql.parse(c,
      select q.sql_text, q.last_load_time, s.*
      from v$sql_shared_cursor s, v$sql q
      where s.sql_id = q.sql_id
          and s.child_number = q.child_number
          and q.sql_id like ‘‘&sql_id‘‘
      order by last_load_time,
      dbms_sql.native);
  dbms_sql.describe_columns(c, col_cnt, col_rec);

  for idx in 1 .. col_cnt loop
    dbms_sql.define_column(c, idx, col_value, 4000);
  end loop;

  ret_val := dbms_sql.execute(c);

  while(dbms_sql.fetch_rows(c) > 0) loop
    for idx in 1 .. col_cnt loop
      dbms_sql.column_value(c, idx, col_value);
      if col_rec(idx).col_name in (SQL_ID, CHILD_NUMBER,LAST_LOAD_TIME) then
        dbms_output.put_line(rpad(col_rec(idx).col_name, 30) ||
                 =  || col_value);
      elsif col_value = Y then
        dbms_output.put_line(rpad(col_rec(idx).col_name, 30) ||
                 =  || col_value);
      end if;

    end loop;

    dbms_output.put_line(--------------------------------------------------);

   end loop;

  dbms_sql.close_cursor(c);

end;
/

 

 

转自《http://kerryosborne.oracle-guy.com/2009/06/oracle-11g-adaptive-cursor-sharing-acs/》

Oracle 11g Adaptive Cursor Sharing (ACS)

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原文地址:http://www.cnblogs.com/polestar/p/5530928.html

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