All connection usage occurs within the scope of either a global transaction or a local transaction containment (LTC) boundary. Each transaction type places different requirements on connections and impacts connection settings differently.
Connection sharing and reuse
You can only share connections within a global transaction scope (assuming other sharing rules are met). However, you can serially reuse connections within an LTC scope. A get/use/close connection pattern followed by another instance of get/use/close (to the same data source or connection factory) enables you to reuse the same connection. See the Unshareable and shareable connections topic for more details.
JDBC AutoCommit behavior
One-phase commit and two-phase commit connections
One-phase commit resources are such that work being done on a one phase connection cannot mix with other connections and ensure that the work done on all of the connections completes or fails atomically. The product does not allow more than one one-phase commit connection in a global transaction. Futhermore, it does not allow a one-phase commit connection in a global transaction with one or more two-phase commit connections. You can coordinate only multiple two-phase commit connections within a global transaction.
WebSphere Application Server provides last participant support that enables a single one-phase commit resource to participate in a global transaction with one or more two-phase commit resources.
WTRN0063E: An illegal attempt to enlist a one phase capable resource with existing two phase capable resources has occurred.
Related concepts
Connection factory
Data sources
Unshareable and shareable connections
Connection handles
Deferred Enlistment
Related tasks
Using the transaction service