A simple script to show a trend through the AWR OS Stats.
rem rem Script: trend_awr_osstat.sql rem Author: Jonathan Lewis rem Dated: Sep 2006 rem Purpose: rem rem Last tested rem 10.2.0.3 rem Not Tested rem 18.104.22.168 rem 22.214.171.124 rem Not relevant rem 126.96.36.199 rem 188.8.131.52 rem rem Warning: rem Requires licence for Diagnostic Pack. rem rem Notes: rem Trendline through AWR OS stats rem rem Accesses data for current instance and DBID rem rem Hard coded to go 30 days back in history rem Ignores database restarts rem rem Reports a timestamp at the start of an interval rem with the activity that happened in that interval rem rem The join on snap_id + 1 is valid for AWR because rem of the way AWR generates snapshot ids. (This is rem not safe for statspack unless you set the sequence rem to nocache). rem rem Change the following define to pick a different statistic rem The available OS stats are platform dependent rem define m_stat_name = 'BUSY_TIME' set timing off set linesize 132 set pagesize 60 set trimspool on column instance_number new_value m_instance noprint column dbid new_value m_dbid noprint select ins.instance_number, db.dbid from v$instance ins, v$database db ; column value format 999,999,999,999 column curr_value format 999,999,999,999 column prev_value format 999,999,999,999 spool trend_awr_osstat with base_line as ( select /*+ materialize */ snp.snap_id, to_char(snp.end_interval_time,'Mon-dd hh24:mi:ss') end_time, ost.value from dba_hist_snapshot snp, dba_hist_osstat ost where snp.dbid = &m_dbid and snp.instance_number = &m_instance and end_interval_time between sysdate - 30 and sysdate /* */ and ost.dbid = snp.dbid and ost.instance_number = snp.instance_number and ost.snap_id = snp.snap_id and ost.stat_name = '&m_stat_name' /* */ ) select b1.end_time start_of_delta, b1.value prev_value, b2.value curr_value, b2.value - b1.value value from base_line b1, base_line b2 where b2.snap_id = b1.snap_id + 1 order by b1.snap_id ; spool off
Update Feb 2010: Remember my warnings about testing any SQL you get from the Internet. This code has behaved reasonably well on most sites I’ve visited – but I was at a site recently that had set their retention time to 18 months, and performance was dire. Workaround: in the subquery, change the simple /*+ materialize */ hint to: /*+ materialize leading(snp ost) no_merge(snp) push_pred(ost) */. Ideally, of course, I’d write something that accessed the wrh$ table directly (in fact, I probably have done so a few times already).