4.5. Request Level Transactions

Request level transactions are used when the request is not in the scope of a global or local transaction, which implies autoCommit is true. In a request level transaction, your application does not need to explicitly call commit or rollback, rather every command is assumed to be its own transaction that will automatically be committed or rolled back by the server.

JBoss Data Virtualization can perform updates through virtual tables. These updates might result in an update against multiple physical systems, even though the application issues the update command against a single virtual table. Often, a user might not know whether the queried tables actually update multiple sources and require a transaction.

For that reason, JBoss Data Virtualization allows your application to automatically wrap commands in transactions when necessary. Because this wrapping incurs a performance penalty for your queries, you can choose from a number of available wrapping modes to suit your environment. You need to choose between the highest degree of integrity and performance your application needs. For example, if your data sources are not transaction-compliant, you might turn transaction wrapping off to maximize performance.