Hello all,

New to the forum and tried to find a topic relating to this but I could not find one.  

I am trying to get some specifics on how an Oracle back end DB would handle data loads on a search and replace by PK scenario?  We use a primary key in order to do a search and replace on a respective table.  One time in the morning we get large batches and incremental updates throughout the day.  We are running Analytics 11.1 with an Oracle backend.  It was mentioned that the IBM software is controlling the row locking during data updates.

So, I am trying to find some specific reading to how, if at all, this might impact our reporting capability to our uses?

Any information is appreciated and I would love to read it.

Thanks to anyone with some information.

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Eldon Freymuth
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#CognosAnalyticswithWatson

This is not a problem in most Cognos + Oracle environments.

By default, the Cognos software will connect to an Oracle database using the default transaction isolation level configured on either the Oracle database client (JDBC driver) or server. 

Personally I would start by googling the Oracle error code that is being returned and see what Oracle recommends to resolve it.


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JASON TAVOULARIS
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Thanks for taking the time to reply.

There is no error.  I am trying to understand, or at least read, a little bit about the science behind the connection.  I was hoping there would be some reference information but I can't find any.  I have googled for hours and thought this would be a good resource.

I just want to understand how, potential, row locking could interfere with reporting.

Thanks,
Eldon

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Eldon Freymuth
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Original Message:
Sent: Wed January 08, 2020 11:55 AM
From: JASON TAVOULARIS
Subject: Row Locking During Data Loads

This is not a problem in most Cognos + Oracle environments.

By default, the Cognos software will connect to an Oracle database using the default transaction isolation level configured on either the Oracle database client (JDBC driver) or server. 

Personally I would start by googling the Oracle error code that is being returned and see what Oracle recommends to resolve it.


------------------------------
JASON TAVOULARIS
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I recommend reading this Wikipedia page understanding that Cognos will be doing exclusively "Read"  the Oracle data server with the default isolation of the Oracle client/server
https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels

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JASON TAVOULARIS
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Original Message:
Sent: Wed January 08, 2020 12:58 PM
From: Eldon Freymuth
Subject: Row Locking During Data Loads

Thanks for taking the time to reply.

There is no error.  I am trying to understand, or at least read, a little bit about the science behind the connection.  I was hoping there would be some reference information but I can't find any.  I have googled for hours and thought this would be a good resource.

I just want to understand how, potential, row locking could interfere with reporting.

Thanks,
Eldon

------------------------------
Eldon Freymuth
------------------------------


Original Message:
Sent: Wed January 08, 2020 11:55 AM
From: JASON TAVOULARIS
Subject: Row Locking During Data Loads

This is not a problem in most Cognos + Oracle environments.

By default, the Cognos software will connect to an Oracle database using the default transaction isolation level configured on either the Oracle database client (JDBC driver) or server. 

Personally I would start by googling the Oracle error code that is being returned and see what Oracle recommends to resolve it.


------------------------------
JASON TAVOULARIS

Amazing page.  Great reading and more references.  Exactly what I needed to continue research.  Thank you very much.

Eldon

------------------------------
Eldon Freymuth
------------------------------

Original Message:
Sent: Wed January 08, 2020 01:55 PM
From: JASON TAVOULARIS
Subject: Row Locking During Data Loads

I recommend reading this Wikipedia page understanding that Cognos will be doing exclusively "Read"  the Oracle data server with the default isolation of the Oracle client/server
https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels

------------------------------
JASON TAVOULARIS
------------------------------


Original Message:
Sent: Wed January 08, 2020 12:58 PM
From: Eldon Freymuth
Subject: Row Locking During Data Loads

Thanks for taking the time to reply.

There is no error.  I am trying to understand, or at least read, a little bit about the science behind the connection.  I was hoping there would be some reference information but I can't find any.  I have googled for hours and thought this would be a good resource.

I just want to understand how, potential, row locking could interfere with reporting.

Thanks,
Eldon

------------------------------
Eldon Freymuth


Original Message:
Sent: Wed January 08, 2020 11:55 AM
From: JASON TAVOULARIS
Subject: Row Locking During Data Loads

This is not a problem in most Cognos + Oracle environments.

By default, the Cognos software will connect to an Oracle database using the default transaction isolation level configured on either the Oracle database client (JDBC driver) or server. 

Personally I would start by googling the Oracle error code that is being returned and see what Oracle recommends to resolve it.


------------------------------
JASON TAVOULARIS

ORACLE will provide read consistency via it's logs.

Potentially, a long running query in an ORACLE environment could encounter snapshot too old aka ORA-01555

See also.

https://www.ibm.com/support/knowledgecenter/SSEP7J_11.1.0/com.ibm.swg.ba.cognos.ug_cra.doc/c_isolationlevels.html

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NIGEL CAMPBELL
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