Class PooledQldbDriver

Note: There is no corresponding open method and the only option is to instantiate another driver.

When this method is invoked, the driver will acquire a Transaction and hand it to the TransactionExecutor you passed via the transactionFunction parameter. Once the transactionFunction's execution is done, the driver will try to commit the transaction. If there is a failure along the way, the driver will retry the entire transaction block. This would mean that your code inside the transactionFunction function should be idempotent.

You can also return the results from the transactionFunction. Here is an example code of executing a transaction

let result = driver.executeLambda(async (txn:TransactionExecutor) => {
  let a = await txn.execute("SELECT a from Table1");
  let b = await txn.execute("SELECT b from Table2");
  return {a: a, b: b};
});

Please keep in mind that the entire transaction will be committed once all the code inside the transactionFunction is executed. So for the above example the values inside the transactionFunction, a and b, are speculative values. If the commit of the transaction fails, the entire transactionFunction will be retried.

The function passed via retryIndicator parameter is invoked whenever there is a failure and the driver is about to retry the transaction. The retryIndicator will be called with the current attempt number.

deprecated

[NOT RECOMMENDED] It is not recommended to use this method during transaction execution. Instead, please use QldbDriver.executeLambda to execute the transaction.

Create and return a newly instantiated QldbSession object. This will implicitly start a new session with QLDB.

throws

DriverClosedError when this driver is closed.