Thread: Transaction Isolation Level

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

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

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
> > 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
>