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postgresqlodoo8.0
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Pavan Teja

Hi Community,

We are facing the error "*could not serialize due to concurrent update*" too 
many times in our production server. 

The errors are occurring due to the "Repeatable Read" isolation level. I 
know that the database default_transaction_isolation is "Read Committed" 
where we don't get these errors. 

But when I monitored the queries the application(ODOO) user is issuing "SET 
default_transaction_isolation to Repeatable Read". So is the cause of these 
errors.  I have explored on the ODOO application side where in which I lost 
somewhere  but found to know that these errors are common for ODOO. 

In one of the ODOO application files named "sql_db.py" the below code I have 
found where I understood the isolation level was set to "Repeatable Read". 

My concern here is if I change this isolation level to "Read Committed" will 
this suffice to stop this error occurrence? 

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OdooBot
Hi,

Did you answer my question??

Looking forward to hearing from you.

Regards, 
Pavan Teja, 
9841380956 

On Wed, 17 Apr, 2019, 12:57 PM Mitul Shingala, <shingalamitul0023@gmail.com> wrote:

A new question Repeated Serialization Errors("could not serialize access due to concurrent update") in Postgres Database on Help has been posted. Click here to access the question :

See question


Sent by Odoo S.A. using Odoo.

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Brain Station 23
Best Answer

Frequently we encounter with this problem that when multiple user(transaction) tries to update a same record/row of a table at the same time, the DBMS fail to serialize the access to the record/row hence throws an error saying, 'could not serialize access due to concurrent update'.Below is the solution that can prevent this kind of data race condition.


with self.env.cr.savepoint():    
	​self.env.cr.execute("SELECT id FROM YOUR_MODEL WHERE id = %s FOR UPDATE", (ID_Of_The_Records_to_lock,))        
	#​ update Records or Any ORM Operation inside the scope

In the code above, when the code execution enters the scope of the savepoint context, we are executing a query to acquire a row level lock on some rows of the table by their ID so that no other transaction can update/modify the same records until the lock is released. The lock will be released when an explicit commit on the cursor is done or a rollback is done.


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