The rollback was necessary for Sybase and other databases at the time, but possibly none anymore... Regardless, it is solved by setting If you set commitRequired="false". In the next major version of iBATIS we'll probably change the default setting.
***BUT*** Creating the transaction in the first place has nothing to do with Sybase. It's a common misconception that transactions are only useful for updates. If you are running multiple selects against a transactional database, you will want to run them in a transaction scope to ensure that you're isolated from other partial changes to the database (depends on isolation level of course). For example (pseudocode): int n = select count(*) from categories; List list = select * from categories; n == list.size() is only guaranteed if both statements were run in an isolated transaction scope. Clinton From: Michael Schall [mailto:[EMAIL PROTECTED] Sent: March-05-08 10:49 AM To: user-java@ibatis.apache.org Subject: Re: queryForList/Map/Object... rollbacks I saw the commitRequired, but why are we creating the transaction in the first place? Or is this a Sybase requirement that the rest of us have had to live with? On Wed, Mar 5, 2008 at 11:44 AM, Christopher Lamey <[EMAIL PROTECTED]> wrote: Doh! Forgot about "commitRequired" - been using Spring for everything lately. Sorry about that. On 3/4/08 7:46 PM, "" <> wrote: > Actually, it is the default behaviour. :-/ > > It's a combination of both the iBATIS transaction manager default > configuration and SimpleDataSource. > > To make a long story short, in the good old days, some JDBC drivers > literally required a rollback to "reset" the connection. *cough* Sybase > *cough* But other drivers hissed and booed at the excessive rollbacks. > > Thus we added a flag to the iBATIS transaction manager, called > commitRequired (because commits are equally as aggressive). Try this: > > <transactionManager ... commitRequired="false"> > > That combined with a container managed DataSource should eliminate all > unnecessary rollbacks. If it was already set to false, it is entirely > possible that SimpleDataSource was entirely responsible for the aggressive > rollbacks -- thus we should probably make that configurable too. > > Clinton > > -----Original Message----- > From: Christopher Lamey [mailto:[EMAIL PROTECTED] > Sent: March-04-08 5:07 PM > To: user-java@ibatis.apache.org > Subject: Re: queryForList/Map/Object... rollbacks > > That is not the default iBATIS behavior, I'm guessing your container is > getting involved. > > From what I understand, the SIMPLE datasource type is generally for > standalone programs, not for apps running in a container. > > On 3/4/08 4:20 PM, "Tom Henricksen" <[EMAIL PROTECTED]> wrote: > >> Currently we are using JDBC with simple datasource. >> >> >> >> <transactionManager type="JDBC"> >> >> <dataSource type="SIMPLE"> >> >> >> >> But we are transitioning to JNDI datasource. >> >> >> >> This is just a web application. I will take a look at the Wiki. >> >> >> >> So is this default behavior of iBatis to create a transaction and roll >> it back for even a select? >> >> >> >> Would JTA change this? >> >> >> >> Thanks, >> >> Tom >> >> >> >> >> >> -----Original Message----- >> From: Jeff Butler [mailto:[EMAIL PROTECTED] >> Sent: Tuesday, March 04, 2008 3:53 PM >> To: user-java@ibatis.apache.org >> Subject: Re: queryForList/Map/Object... rollbacks >> >> >> >> What transaction manager are you using? >> >> Is this an EJB application with CMT, or just a web application? >> >> Have you read the information in the WIKI about configuring iBATIS on >> WebSphere? >> >> >> >> http://opensource.atlassian.com/confluence/oss/display/IBATIS/Environmen >> t+Specific+Information >> >> >> >> Jeff Butler >> >> >> >> >> >> On Tue, Mar 4, 2008 at 3:32 PM, Tom Henricksen <[EMAIL PROTECTED]> wrote: >> >> We are performance monitoring our application and my DBA let me know >> that we had over 3 MILLION rollbacks in a single day. We are using >> WebSphere to DB2 on Win2k3 servers. >> >> I looked in our code and could not find anything. Used p6spy and found >> that every time queryForXXX is called I received a rollback. Stepping >> through the queryForList code in SqlMapExecutorDelegate.java the >> autoStartTransaction starts a transaction if none is present and since >> we don't have commitRequired set, the autoEndTransaction will cause a >> rollback. >> >> I assume there is a good reason to start the transaction here. It seems >> like extra work creating a transaction that will always be rolled back. >> Can someone explain why this is good to me so I can forward the >> information to my DBA? Any links supporting the argument would be >> great. Is there a way to use the queryForXXX without creating a >> transaction? I assume it is better to not have commitRequired? >> >> Thanks for your time. >> >> >> >> Tom Henricksen >> Consultant >> Advanced Technologies Group, Inc. >> >> >> >> >> >
