Hi Paresh,
If you want to find the root cause of the sql performance i suggest you
provide :
++++++++++++++++
1. the AWR report from both executions ( good and bad)
2. SQLT XTRACT from both sql ids.
Please , for this sql id , provide the output from the SQLT utility, using
the XTRACT method (it is important use this method for this issue) for:
--- The XTRACT method will take the SQLID of the problem SQL as input and
will *NOT* execute the SQL.
--- For information on obtaining and using SQLT, please refer to:
SQLT Usage Instructions (Doc ID 1614107.1)
For example the following file is from a successful SQLT run using the
XTRACT method:
sqlt_s45774_xtract_fp48hh5dkm529.zip
++++++++++++++++
If you can open a SR then that it would be easier for support to assist
you ;)
Rgds,
Sachin Pawar
https://twitter.com/sach_pwr
On Fri, Aug 17, 2018 at 1:33 PM Tim Gorman <tim.evdbt@xxxxxxxxx> wrote:
Paresh,
As another suggestion, please think more about the appropriateness of
using an AWR report for tuning a specific process?
An AWR report consists of information gathered for a database instance or
all the instances in a RAC cluster, which is an enormous amount of
information pertaining to many processes. You are trying to tune a
specific process, so you have already arrived at the endpoint of AWR
analysis, which is identifying a SQL statement or process within an
instance or cluster, and you are ready to begin the next step by examining
the process in detail using SQL tracing.
So please consider learning more about SQL tracing and TKPROF (and similar
utilities), about which numerous books, blog post articles, and Oracle
documentation has been written. AWR reports will not provide much
assistance to you for this task.
The other consideration is that this email list is not Oracle Support. If
you or your company has Oracle licenses, then you have the resources of
Oracle Support to assist you. They have an instructive process for
resolving such cases. There is evidently urgency implied in your emails to
this list, and if there is indeed urgency for resolving this situation,
then working this case with Oracle Support is the most responsible thing
for you to do. This list will be useful for helping you understand what
Oracle Support asks you to do, but we are not your support organization.
Hope this helps...
-Tim
On 8/17/18 09:59, Powell, Mark wrote:
Paresh, for help with a query performance issue you should post the SQL
and actual query plan in use by Oracle. Most often when query performance
drastically changes there has been a change in the plan due to a change in
statistics, bind variable peek, adaptive query plan, etc...
Mark Powell
Database Administration
(313) 592-5148
------------------------------
*From:* oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx>
<oracle-l-bounce@xxxxxxxxxxxxx> on behalf of paresh.gandhi@xxxxxxxxx
<paresh.gandhi@xxxxxxxxx> <paresh.gandhi@xxxxxxxxx>
*Sent:* Friday, August 17, 2018 12:47:36 PM
*To:* oracle-l@xxxxxxxxxxxxx
*Subject:* Re: SQL performance issue
Dear all,
Could someone shed some light on this please?
Thanks
Paresh
On Tue, 14 Aug 2018, 15:48 Paresh Gandhi, <paresh.gandhi@xxxxxxxxx> wrote:
Hello,
I am stuck against a performance issue that was reported recently.
The issue I am currently looking at is about a job that takes 1 hour as
opposed to 20 minutes in the past. This is happening since we switched over
from primary to secondary site. Both sites are two-node rac databases. On
primary site this used to take 20 mins. We also ran this in pre-prod
environment and it takes roughly 20 mins.
I had taken a look at the AWR report from both pre-prod and PROD
databases. There is no single query that is taking long. However, there is
a query that runs for 13,000 times and is taking 0.23 seconds per execution
as opposed to 0.05 against pre-prod. This explains the additional time
taken in PROD (i.e. new PROD). Please note that the plan hash value for the
SQL_ID in both environments is exactly the same.
Top wait events in PROD suggests high DB CPU and cluster related wait
events. So I suspect there is something down to getting blocks from the
resource master instance for the blocks in question. Please could someone
help?
Database version is 11.2.0.4.
All the details are listed in the attached files.
I would greatly appreciate if you could share your views with me.
Many thanks
Paresh
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