pyqldb.driver.base_qldb_driver.BaseQldbDriver(ledger_name, retry_limit=4, read_ahead=0, executor=None, region_name=None, verify=None, endpoint_url=None, aws_access_key_id=None, aws_secret_access_key=None, aws_session_token=None, config=None, boto3_session=None)[source]¶An abstract base class representing a factory for creating sessions.
ledger_name (str) – The QLDB ledger name.
retry_limit (int) – The number of automatic retries for statement executions using convenience methods on sessions when an OCC conflict or retriable exception occurs. This value must not be negative.
read_ahead (int) – The number of read-ahead buffers. Determines the maximum number of statement result pages that can be buffered in memory. This value must be either 0, to disable read-ahead, or a minimum of 2.
executor (concurrent.futures.thread.ThreadPoolExecutor) – A specific, optional, executor to be used by the retrieval thread if read-ahead is enabled.
region_name (str) – See [1].
verify (bool/str) – See [1].
endpoint_url (str) – See [1].
aws_access_key_id (str) – See [1].
aws_secret_access_key (str) – See [1].
aws_session_token (str) – See [1].
config (botocore.config.Config) – See [2]. Note that parameter user_agent_extra will be overwritten.
boto3_session (boto3.session.Session) – The boto3 session to create the client with (see [1]). The boto3 session is expected to be
configured correctly.
TypeError – When config is not an instance of botocore.config.Config.
When boto3_session is not an instance of boto3.session.Session.
ValueError – When read_ahead or retry_limit is not set to the allowed values specified.
[1]: Boto3 Session.client Reference.
[2]: Botocore Config Reference.
read_ahead¶The number of read-ahead buffers to be made available per StreamCursor instantiated by this driver. Determines the maximum number of result pages that can be buffered in memory.
retry_limit¶The number of automatic retries for statement executions using convenience methods on sessions when an OCC conflict or retriable exception occurs.