[Oracle-l] Simple insert - 36,000 physical reads

Indexes?



From: oracle-l-bounce_at_freelists.org
On Behalf Of Dennis Williams
Sent: Friday, December 12, 2008 2:55 PM
To: oracle-l_at_freelists.org
Subject: Simple insert - 36,000 physical reads



List,



Oracle 10.2.0.4, Solaris 8



I've found a simple insert that has:

1 execution

2,512,102 Buffer Gets

36,479 Physical Reads

1 Parse call

1 Row



This insert statement appears quite a few times in the AWR report, and
for the times I see it, the statistics are pretty close to what I've
listed. The insert just has a list of columns and a list of values. No
subqueries. There is a TO_DATE conversion on two columns.This is a real
table, not a view.



Does anyone have any suggestions of why a simple insert could cause this
much database activity?



Thanks to Brandon for suggesting awrsqrpt.sql in response to another
question. That is a great tool.



Dennis Williams

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Explain plan?



From: oracle-l-bounce_at_freelists.org
On Behalf Of Stephens, Chris
Sent: Friday, December 12, 2008 2:57 PM
To: oracledba.williams_at_gmail.com; oracle-l_at_freelists.org
Subject: RE: Simple insert - 36,000 physical reads



Indexes?



From: oracle-l-bounce_at_freelists.org
On Behalf Of Dennis Williams
Sent: Friday, December 12, 2008 2:55 PM
To: oracle-l_at_freelists.org
Subject: Simple insert - 36,000 physical reads



List,



Oracle 10.2.0.4, Solaris 8



I've found a simple insert that has:

1 execution

2,512,102 Buffer Gets

36,479 Physical Reads

1 Parse call

1 Row



This insert statement appears quite a few times in the AWR report, and for
the times I see it, the statistics are pretty close to what I've listed.
The insert just has a list of columns and a list of values. No subqueries.
There is a TO_DATE conversion on two columns.This is a real table, not a
view.



Does anyone have any suggestions of why a simple insert could cause this
much database activity?



Thanks to Brandon for suggesting awrsqrpt.sql in response to another
question. That is a great tool.



Dennis Williams



CONFIDENTIALITY NOTICE:

This message is intended for the use of the individual or entity to which
it is addressed and may contain information that is privileged,
confidential and exempt from disclosure under applicable law. If the
reader of this message is not the intended recipient or the employee or
agent responsible for delivering this message to the intended recipient,
you are hereby notified that any dissemination, distribution or copying of
this communication is strictly prohibited. If you have received this
communication in error, please notify us immediately by email reply.

Triggers could do it.



From: oracle-l-bounce_at_freelists.org
On Behalf Of Dennis Williams
Sent: Friday, December 12, 2008 3:55 PM
To: oracle-l_at_freelists.org
Subject: Simple insert - 36,000 physical reads



List,



Oracle 10.2.0.4, Solaris 8



I've found a simple insert that has:

1 execution

2,512,102 Buffer Gets

36,479 Physical Reads

1 Parse call

1 Row



This insert statement appears quite a few times in the AWR report, and for
the times I see it, the statistics are pretty close to what I've listed. The
insert just has a list of columns and a list of values. No subqueries. There
is a TO_DATE conversion on two columns.This is a real table, not a view.



Does anyone have any suggestions of why a simple insert could cause this
much database activity?



Thanks to Brandon for suggesting awrsqrpt.sql in response to another
question. That is a great tool.



Dennis Williams

Are the values for the insert are straight values or any home-grown
function calls that generates the values?



Regards,
Santhosh Channa

From: oracle-l-bounce_at_freelists.org
On Behalf Of Dennis Williams
Sent: Friday, December 12, 2008 3:55 PM
To: oracle-l_at_freelists.org
Subject: Simple insert - 36,000 physical reads



List,



Oracle 10.2.0.4 <http://10.2.0.4>, Solaris 8



I've found a simple insert that has:

1 execution

2,512,102 Buffer Gets

36,479 Physical Reads

1 Parse call

1 Row



This insert statement appears quite a few times in the AWR report, and
for the times I see it, the statistics are pretty close to what I've
listed. The insert just has a list of columns and a list of values. No
subqueries. There is a TO_DATE conversion on two columns.This is a real
table, not a view.



Does anyone have any suggestions of why a simple insert could cause this
much database activity?



Thanks to Brandon for suggesting awrsqrpt.sql in response to another
question. That is a great tool.



Dennis Williams

Lots of indexes on the tables could also cause additional pio attributed to
main query. possible fk validations ?

Raj

On Fri, Dec 12, 2008 at 3:55 PM, Dennis Williams <
oracledba.williams_at_gmail.com> wrote:

Trigger(s)?

If you grab the SQL and run it yourself in a session manually (using
autotrace or sql trace) do you see the same effect ?

For things like this a SQL trace would also reveal where the IO takes place
(file#, block#) and any recursive sql occurring through triggers, vpd, or
whatever else there might be.

Stefan

Stefan P Knecht
Senior Consultant
Systems Engineering

OPITZ CONSULTING Schweiz GmbH
Seestrasse 97
CH-8800 Thalwil

Mobile +41-79-571 36 27
stefan.knecht_at_opitz-consulting.ch
http://www.opitz-consulting.ch

OCP 9i/10g SCSA SCNA

On Fri, Dec 12, 2008 at 9:55 PM, Dennis Williams <
oracledba.williams_at_gmail.com> wrote:

a foreign key constraint on a column that is not indexed ?

Bjoern