CreateReadSessionRequest(mapping=None, *, ignore_unknown_fields=False, **kwargs)Request message for CreateReadSession.
Attributes
| Name | Description |
| parent |
str
Required. The request project that owns the session, in the form of ``projects/{project_id}``. |
| read_session |
google.cloud.bigquery_storage_v1.types.ReadSession
Required. Session to be created. |
| max_stream_count |
int
Max initial number of streams. If unset or zero, the server will provide a value of streams so as to produce reasonable throughput. Must be non-negative. The number of streams may be lower than the requested number, depending on the amount parallelism that is reasonable for the table. There is a default system max limit of 1,000. This must be greater than or equal to preferred_min_stream_count. Typically, clients should either leave this unset to let the system to determine an upper bound OR set this a size for the maximum "units of work" it can gracefully handle. |
| preferred_min_stream_count |
int
The minimum preferred stream count. This parameter can be used to inform the service that there is a desired lower bound on the number of streams. This is typically a target parallelism of the client (e.g. a Spark cluster with N-workers would set this to a low multiple of N to ensure good cluster utilization). The system will make a best effort to provide at least this number of streams, but in some cases might provide less. |