Do I need a distributed transaction ?

[sboulay]

I was wondering if this is possible without the use of JTA
I have DAO that a Business Object uses ... and transactions are currently declared at this level via spring declarative transaction managment (On the business service that is). The datasource is currently against one database. Is it possible to use another dao inside this business object that makes a read only call to another database ?

--> transaction declared to start @ service level in application conifig against local system
public MyService {

--> Call external system to get read only value from DAO1
--> Insert into local system value received from external system using DAO2

}

[irbouho]

AFAIK JTA allows to synchronize multiple database access (insert, update, delete). As you need a read only access to database 2, you do not have to synchronize that r/o access with the ongoing transaction. So you do not need to use JTA for this case.

[katentim]

It's certainly possible without JTA. If you are doing a read only call on DB2 (you are) and all other access to it is not distributed across the two DB (it sounds like it isn't) you won't get stale reads, so you are OK.