RE: explain plan, can you explain this?

From: Yasin Baskan <>
Date: Fri, 11 Jan 2008 11:04:51 +0200
Message-ID: <083667B535F3464CA0DD0D1DAFA4E3760F667B4B@camexc1.kfs.local>

Andrew, AWR reports delta values, not cumulative statistics.  

It reports the delta values from the columns of dba_hist_sqlstat like buffer_gets_delta.  

Here is a part of an sql run by a 10.2 awrrpt.sql  


sum(disk_reads_delta) dskr, sum(executions_delta) exec,  

                      sum(cpu_time_delta) cput, sum(elapsed_time_delta)


from dba_hist_sqlstat

                  where dbid

      = :dbid

                    and instance_number = :inst_num


          and :bid            < snap_id

                    and snap_id

   <= :eid

               group by sql_id)


From: Andrew Kerber [] Sent: Thursday, January 10, 2008 7:57 PM To:
Cc: Yasin Baskan;; Oracle L Subject: Re: explain plan, can you explain this?  

And then, you have to do it again for AWR. AWR does report cumulative statistics.

On Jan 10, 2008 11:36 AM, John Kanagaraj < > wrote:

> John, are you sure that statspack reports sql statistics cumulatively?

Yasin and Allen,

You are right: My bad. STATSPACK indeed does report the differences. This myth of mine was self-created, probably from early days of STATSPACK. Thank you for setting me right. This reminds me once more to re-validate everything I know.


John Kanagaraj <><
DB Soft Inc (Sorry - not an Oracle blog!)
** The opinions and facts contained in this message are entirely mine
and do not reflect those of my employer or customers ** 

Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.' 

Received on Fri Jan 11 2008 - 03:04:51 CST

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