Open JPA recommended driver for DB2

Hi, We are using DB2 LUW 9.1 fixpack 4 as our Database. Could you please recommend which driver (XA or non XA) is suitable for openJPA 1.2.0 and DB2. We use transactions a lot while doing inserts/updates/retrive operations. Thanks, Chandra -- View this message in context: http://n2.nabble

Re: OpenJpa, and DB2 shared lock

Hi Chandra, Interesting data. First thing I noticed is that all of that exception trace data happens for the same deadlock/timeout exception. There is no retry logic that I can see. The exception is first reported at 12:27:54:977 and the last log messages for this exception (before you break out

Re: Open JPA recommended driver for DB2

Personally, if your processing does not require the use of XA, then I would stick with non-XA. XA is used when you have multiple resources participating in a transaction. So, besides the driver itself, there is also the transaction processing within the app server that may have additional overhea

Re: OpenJpa, and DB2 shared lock

Hi Chandra, can you provide more details on the Spring side of your app, like what version of Spring you're using and what if any annotations are being used, like the @Transactional for Spring or JPA annotations? Are you solely using annotations or do you have a persistence.xml and/or orm.xml

Re: Open JPA recommended driver for DB2

Hi Kevin, What exactly is multiple resources mean? We are using Websphere 6.1 Feature pack 3. One of the reason why we are thinking about using XA driver is if we have a database timeout of 30 sec, if we use non-xa drivers the database transaction from OpenJpa tries unlimited before we force it

Re: Open JPA recommended driver for DB2

Hi Chandra - XA is a standard for distributed transactions and usually refers to situations where multiple databases are used in a combined transaction. This is a big subject. You might get a start here - http://en.wikipedia.org/wiki/X/Open_XA - Paul On 4/27/2009 10:03 AM, Chand

Using MappedSuperclass with UniqueConstraint

Hi, defining constraints on a mapped superclass does not work with OpenJPA (tried with 2.0.0-snapshot, but I guess it's the same with 1.x-releases). Example: @MappedSuperclass @Table(uniqueConstraints = @UniqueConstraint(columnNames = "name")) public abstract class NamedEntity { String name;

Re: OpenJpa, and DB2 shared lock

Kevin, My answers below in Bold.. I'm attaching the SystemErr.log file here that may have the same info as the trace. http://n2.nabble.com/file/n2727497/SystemErr_Update_lock_testing.log SystemErr_Update_lock_testing.log Thanks, Chandra Kevin Sutter wrote: > > Hi Chandra, > Interesting d

Re: Using MappedSuperclass with UniqueConstraint

Ah, I see something similar has been posted recently, but without definitive answer: http://n2.nabble.com/UniqueConstraint-in-a-MappedSuperclass-not-working-tc2633410.html Seems not to be an entirely unreasonable use case, given that Eclipselink and Hibernate support it (according to the above p

Re: Open JPA recommended driver for DB2

Hi Chandra, More interesting data... :-) So, you are saying that if you use the JDBC XA driver with DB2 and WAS v6.1 with the EJB3 Feature Pack, then you do not experience the problem we've been discussing in the other thread [1]? Everything else is the same, just a different JDBC driver? And, t

Re: Open JPA recommended driver for DB2

Hi Kevin, Yes. We donot experience the problem if we use XA drivers. But we have tested that problem for only updates but not inserts. Remeber that (see Thread 1) non-XA drivers timed out fine for inserts and did not time out for updates. For XA drivers we tested only updates. We couldn't test i

Re: Open JPA recommended driver for DB2

Hi Kevin, one more thing.. We use Websphere Datasources that use these drivers.. Thanks, Chandra Kevin Sutter wrote: > > Hi Chandra, > More interesting data... :-) So, you are saying that if you use the JDBC > XA driver with DB2 and WAS v6.1 with the EJB3 Feature Pack, then you do > not >

Re: Open JPA recommended driver for DB2

Thanks Paul! It gave me some info about the XA transactions. Chandra Paul Copeland wrote: > > Hi Chandra - > > XA is a standard for distributed transactions and usually refers to > situations where multiple databases are used in a combined transaction. > This is a big subject. You might

Re: Performance issues

Hi, Paul, Thank you for sharing your experience. You've given me some very good hints. I'll continue to play around with this and maybe post more questions later. Cheers, =David On Sun, 2009-04-26 at 22:39 -0700, Paul Copeland wrote: > Hi David - > > No I did not say that at all. Just that