Re: [SPAM] - Re: [SPAM] - Re: JDBC HighLoad - Found word(s) - Mailing list pgsql-jdbc

But with this usage i cannot reuse a preparedStatement.
Is it possible to create the preparedStatement in the constructor and
reused them
for each update. So that each thread has his own preparedStatements because
each thread do an update every second, i also think that preparedStatements
was  good to use in this configuration but in your usage i have to
prepare the statement each time i get the connection.

Dave Cramer wrote:

> Stephane,
>
> No.
>
> Here is the basic usage of the connection ( regardless of the
> existance of the pool)
>
> get the connection
> prepare the statement
> execute the statement
> do something with result
> close statement
> close connection ( this allows the connection to be re-used by another
> request )
>
>
> Having a pool does not change this pattern.
>
> All the pool does is cache connections so that they can be re-used by
> multiple threads without going through the overhead of opening the
> connection.
> It also minimizes the number of connections required for an
> application. For example if you have 1000 requests you might only need
> 100 connections since they will share
> the connections in the pool.
>
> Dave
>
> Stéphane RIFF wrote:
>
>> I thought that preparedStatement know what connection to use even if
>> i return it to the pool
>>
>> Dave Cramer wrote:
>>
>>> Stephane,
>>>
>>> Yes, that is true, but where do you get the connection from on the
>>> next iteration of the loop ? The constructor of SQLoader.... so the
>>> next loop it is gone.
>>>
>>> Dave
>>>
>>> Stéphane RIFF wrote:
>>>
>>>> I thought that the m_conn.close() released the connection to the
>>>> pool doesn't it ?
>>>> If i close the connection at the end of the loop byt a
>>>> SQLoader.close() this will
>>>> make one connection for each thread. I want each thread ask a
>>>> connection to the pool
>>>> and released it after each update.
>>>>
>>>> Thanks for your time
>>>> Bye
>>>>
>>>> Kris Jurka wrote:
>>>>
>>>>> On Fri, 4 Feb 2005, [ISO-8859-1] St�phane RIFF wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Hello,
>>>>>> I implement like you said in the last post but now i get some
>>>>>> errors like this :
>>>>>>
>>>>>> 2005-02-04 09:03:26,234 : [WARN] SQLoader -
>>>>>> java.sql.SQLException:
>>>>>> org.apache.commons.dbcp.DelegatingPreparedStatement is closed.
>>>>>> I attach the two class i you want to see
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Your main loop is written:
>>>>>
>>>>> SQLoader sl = new SQLoader();
>>>>> for(int i=0;i<100;i++) {
>>>>>    sl.saveTrame( ... );
>>>>> }
>>>>>
>>>>> but the end of the saveTrame method you have:
>>>>>
>>>>> finally {
>>>>>    try {
>>>>>        m_conn.commit();
>>>>>        m_conn.close();
>>>>>
>>>>> This closes the connection on the first iteration of the loop.
>>>>> I'd suggest something like adding SQLoader.close() which gets
>>>>> called at the end of the for loop.
>>>>>
>>>>> Kris Jurka
>>>>>
>>>>> ---------------------------(end of
>>>>> broadcast)---------------------------
>>>>> TIP 8: explain analyze is your friend
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>>
>



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