Where should you put COMMIT and ROLLBACK in a worker?

In a worker that processes tasks using transactions, a COMMIT should be issued after the successful completion of all operations related to the task to record the changes in the database. If an error occurs during processing, a ROLLBACK should be performed to undo all changes and maintain data consistency.

Example in Go using a database:

func processTask(tx *sql.Tx, task Task) error {
    // Processing the task
    err := doWork(tx, task)
    if err != nil {
        tx.Rollback() // Rollback on error
        return err
    }
    return tx.Commit() // Commit on success
}

Thus, COMMIT is placed at the end of successful processing, and ROLLBACK in case of errors to avoid partially applied changes.