Transaction Isolation Level

Started by Grace C. Unsonabout 22 years ago3 messagesgeneral
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#1Grace C. Unson
gracec@ntsp.nec.co.jp

Hello.

How is it possible that ResultSetObjInstance in this statement

ResultSetObjInstance = PreparedObjInstance.executeQuery()

contains this column and value respectively:

TRANSACTION ISOLATION LEVEL , READ_COMMITTED ?

---
Note:
During the query operation, lots of write operations are going
simultaneously in the DB. If this is the reason of the "not-expected" value
above, why is it returned and not thrown as exception?

Any light on this matter is greatly appreciated.

Thank you.

Grace

#2Kris Jurka
books@ejurka.com
In reply to: Grace C. Unson (#1)
Re: Transaction Isolation Level

On Thu, 25 Mar 2004, Grace C. Unson wrote:

Hello.

How is it possible that ResultSetObjInstance in this statement

ResultSetObjInstance = PreparedObjInstance.executeQuery()

contains this column and value respectively:

TRANSACTION ISOLATION LEVEL , READ_COMMITTED ?

---
Note:
During the query operation, lots of write operations are going
simultaneously in the DB. If this is the reason of the "not-expected" value
above, why is it returned and not thrown as exception?

This could be an indication of a thread safety problem in the driver. Are
you using multiple threads on the same connection? The only code (other
than your own) that could generate that ResultSet would be calling
Connection.getTransactionIsolation() do you have any of these calls in
your code?

What version of the driver are you using?

Kris Jurka

#3Grace C. Unson
gracec@ntsp.nec.co.jp
In reply to: Grace C. Unson (#1)
Re: Transaction Isolation Level

Hello Kris,

I appreciate your immediate reply. Thanks.

I'm currently using the Driver version: PostgreSQL 7.3.1 JDBC3 jdbc driver
build 108

No, we don't invoke getTransactionIsolation() in our codes.
Is it the only way we can get this value = "TRANSACTION ISOLATION LEVEL :
READ_COMMITTED" ?

This problem is hard to reproduce. What can you suggest I do to determine
the cause of the problem?

Thank you so much for your time.

---
Grace

----- Original Message -----
From: "Kris Jurka" <books@ejurka.com>
To: "Grace C. Unson" <gracec@ntsp.nec.co.jp>
Cc: <pgsql-general@postgresql.org>
Sent: Thursday, March 25, 2004 6:55 AM
Subject: Re: [GENERAL] Transaction Isolation Level

On Thu, 25 Mar 2004, Grace C. Unson wrote:

Hello.

How is it possible that ResultSetObjInstance in this statement

ResultSetObjInstance = PreparedObjInstance.executeQuery()

contains this column and value respectively:

TRANSACTION ISOLATION LEVEL , READ_COMMITTED ?

---
Note:
During the query operation, lots of write operations are going
simultaneously in the DB. If this is the reason of the "not-expected"

value

Show quoted text

above, why is it returned and not thrown as exception?

This could be an indication of a thread safety problem in the driver. Are
you using multiple threads on the same connection? The only code (other
than your own) that could generate that ResultSet would be calling
Connection.getTransactionIsolation() do you have any of these calls in
your code?

What version of the driver are you using?

Kris Jurka