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From Ejaz X Mohammed <ejaz.moham...@jpmorgan.com>
Subject RE: Locks
Date Wed, 14 Apr 2010 18:11:03 GMT
ok. let me try TRANSACTION_READ_UNCOMMITTED and check locks ...

Ejaz

-----Original Message-----
From: Jeff Butler [mailto:jeffgbutler@gmail.com] 
Sent: Wednesday, April 14, 2010 11:55 AM
To: user-java@ibatis.apache.org
Subject: Re: Locks

iBATIS always starts a transaction.  If you want to avoid transactions
completely, you will need to implement your own version of a
transaction manager - you can base it on the EXTERNAL transaction
manager.

Jeff Butler


On Wed, Apr 14, 2010 at 11:43 AM, Ejaz X Mohammed
<ejaz.mohammed@jpmorgan.com> wrote:
> I changed the code to use plain jdbc instead of ibatis ... as I said I'm doing just SELECT
... I started no tranasaction .. now I don't see any locks, perf seems to be better too ...
>
> If we start a transaction, sybase takes locks ... read lock for SELECT ...
>
> Can we avoid starting TX during select in ibatis?
>
> Ejaz
>
>
> -----Original Message-----
> From: Jeff Butler [mailto:jeffgbutler@gmail.com]
> Sent: Wednesday, April 14, 2010 11:36 AM
> To: user-java@ibatis.apache.org
> Subject: Re: Locks
>
> I assume you're using SIMPLE datasource.  With that data source, the
> isolation level is set as a driver default.  I just did a quick test
> with HSQLDB and the default seems to be TRANSACTION_READ_COMMITTED - a
> middle of the road isolation level.  Maybe there is some setting on
> the Sybase driver that will allow you to change the default isolation
> level?
>
> Alternatively, you can do it in code like this:
>
> try {
>  sqlMapClient.startTransaction(Connection.TRANSACTION_READ_UNCOMMITTED);
>
>  -- do some work
> } finally {
>  sqlMapClient.endTransaction();
> }
>
> If you are using some other datasource (like JNDI), then you'll need
> to look to that datasource for information about changing the
> isolation level.
>
> Jeff Butler
>
>
>
>
>
> On Wed, Apr 14, 2010 at 9:51 AM, Ejaz X Mohammed
> <ejaz.mohammed@jpmorgan.com> wrote:
>> These are my settings ...
>>
>>    <!--
>>    These settings control SqlMap configuration details, primarily to do with transaction
>>    management. They are all optional (see the Developer Guide for more).
>>    -->
>>    <settings
>>            cacheModelsEnabled="true"
>>            enhancementEnabled="true"
>>            lazyLoadingEnabled="true"
>>            maxRequests="32"
>>            maxSessions="10"
>>            maxTransactions="5"
>>            useStatementNamespaces="true"
>>        />
>>
>>    <!--
>>    Configure a datasource to use with this SQL Map using SimpleDataSource.
>>    Notice the use of the properties from the above resource
>>    -->
>>    <transactionManager type="JDBC" >
>>        <dataSource type="....">
>>            <property name="JDBC.Driver" value="${jdbc.driver}"/>
>>            <property name="JDBC.ConnectionURL" value="${jdbc.url}"/>
>>            <property name="JDBC.Username" value="${jdbc.user}"/>
>>            <property name="JDBC.Password" value="${jdbc.password}"/>
>>            <property name="JDBC.DefaultAutoCommit" value="true"/>
>>        </dataSource>
>>    </transactionManager>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Jeff Butler [mailto:jeffgbutler@gmail.com]
>> Sent: Wednesday, April 14, 2010 9:44 AM
>> To: user-java@ibatis.apache.org
>> Subject: Re: Locks
>>
>> It's dependent on the transaction isolation level set on your
>> connection.  There are many variables involved - what is your
>> environment (POOLED, UNPOOLED, JNDI, etc.)?
>>
>> Jeff Butler
>>
>>
>> On Wed, Apr 14, 2010 at 9:38 AM, Ejaz X Mohammed
>> <ejaz.mohammed@jpmorgan.com> wrote:
>>> Hello,
>>>
>>>
>>>
>>> I have an application running on Sybase. DBAs tell me that it is generating
>>> too many locks ... I know that all I'm doing is SELECT.
>>>
>>>
>>>
>>> I'm not sure how SELECT can create locks in database.
>>>
>>>
>>>
>>> Any suggestions ?
>>>
>>>
>>>
>>> Thanks
>>>
>>> Ejaz
>>>
>>> This email is confidential and subject to important disclaimers and
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>
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