partitionRead method

Future<PartitionResponse> partitionRead(PartitionReadRequest request, String session, { String? $fields, })

Creates a set of partition tokens that can be used to execute a read operation in parallel.

Each of the returned partition tokens can be used by StreamingRead to specify a subset of the read result to read. The same session and read-only transaction must be used by the PartitionReadRequest used to create the partition tokens and the ReadRequests that use the partition tokens. There are no ordering guarantees on rows returned among the returned partition tokens, or even within each individual StreamingRead call issued with a partition_token. Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it is not possible to resume the read, and the whole operation must be restarted from the beginning.

request - The metadata request object.

Request parameters:

session - Required. The session used to create the partitions. Value must have pattern ^projects/\[^/\]+/instances/\[^/\]+/databases/\[^/\]+/sessions/\[^/\]+$.

$fields - Selector specifying which fields to include in a partial response.

Completes with a PartitionResponse.

Completes with a commons.ApiRequestError if the API endpoint returned an error.

If the used http.Client completes with an error when making a REST call, this method will complete with the same error.

Implementation

async.Future<PartitionResponse> partitionRead(
  PartitionReadRequest request,
  core.String session, {
  core.String? $fields,
}) async {
  final body_ = convert.json.encode(request);
  final queryParams_ = <core.String, core.List<core.String>>{
    if ($fields != null) 'fields': [$fields],
  };

  final url_ = 'v1/' + core.Uri.encodeFull('$session') + ':partitionRead';

  final response_ = await _requester.request(
    url_,
    'POST',
    body: body_,
    queryParams: queryParams_,
  );
  return PartitionResponse.fromJson(
      response_ as core.Map<core.String, core.dynamic>);
}