Statement.setQueryTimeout() is required to be implemented in order to
achieve compliance with the JDBC specification. I would expect that
current JDBC drivers from the majority of the JDBC driver companies have
implemented this hopefully in a manner that works most of the time.
Marc Prud'hommeaux wrote:
FYI, setQueryTimeout() will meter call Statement.setQueryTimeout() on
the underlying driver. JDBC drivers frequently either don't implement
this, or their implementation is very flawed. Unfortunately, we
haven't done detailed analyses of which drivers properly implement it
or not, so I don't know if DB2 has a proper implementation of it.
One way to test our whether it is supported is to write a small
stand-alone test case that directly creates a JDBC Connection and
tries to execute a slow or blocking SQL statement on a Statement after
you call setQueryTimeout() and see if it correctly times out. If it
doesn't, then the problem is with the driver. If it does, then there's
something wrong with OpenJPA and we can investigate further.
On Mar 22, 2007, at 4:47 PM, Don Brady wrote:
Hi,
I hope this is not off-topic on this list, but I cannot seem to get
QueryTimeout to work, using the persistence.xml below under WebSphere
6.1 with a DB2 connection pool defined in WebSphere, under OpenJPA
0.9.6.
It seems to just ignore the timeout specified and run to completion
no longer how long it takes.
I was wondering if the below should work or if there is another way
of setting a query timeout. I cannot find one.
Actually if I wrap it in a transaction, then I can set a timeout on
the transaction and that does work. But I was avoiding using a
transaction on the basis of advice in the book "Pro EJB" to omit
transactions if they are not needed, in the case of a read-only
query, because they may incur a performance penalty. Would that be
true in OpenJPA for a large read-only query or should I just use a
transaction and set the timeout on that?
Thank you for any comments!
Don
persistence.xml contents:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
xmlns="http://java.sun.com/xml/ns/persistence";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd";>
<persistence-unit name="mpu-prod" transaction-type="JTA">
<provider>
org.apache.openjpa.persistence.PersistenceProviderImpl
</provider>
<jta-data-source>jdbc/mship-prod</jta-data-source>
<non-jta-data-source>jdbc/mship-prod</non-jta-data-source>
<mapping-file>META-INF/orm-prod.xml</mapping-file>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="openjpa.jdbc.Schema" value="PROD" />
<property name="openjpa.DataCache" value="false" />
<property name="openjpa.RemoteCommitProvider"
value="sjvm" />
<property name="openjpa.Log"
value="DefaultLevel=WARN, Runtime=INFO, Tool=INFO,
SQL=TRACE" />
<property name="openjpa.jdbc.DBDictionary"
value="db2(StoreCharsAsNumbers=false)" />
<property name="openjpa.TransactionMode" value="managed" />
<property name="openjpa.jdbc.TransactionIsolation"
value="read-committed" />
<property name="openjpa.ConnectionFactoryMode"
value="managed" />
<property name="openjpa.ConnectionFactoryProperties"
value="QueryTimeout=30"/>
</properties>
</persistence-unit>
</persistence>
