frontend/proto/partition_token.proto

//
// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

syntax = "proto2";

package google.spanner.emulator.frontend;

import "google/protobuf/struct.proto";
import "google/spanner/v1/keys.proto";
import "google/spanner/v1/type.proto";

// Partition token returned in PartitionQuery/PartitionRead. A partition token
// can only be used for reads in the session/transaction it was created in.
//
// Parition token encapsulates the original read/query parameters, such that any
// subsequent read/query request can validate that the partition token is valid.
//
// Partition token also contains information about the partition to read/query.
// Each partition corresponds to a subset of rows such that all partitions
// together return the full result set.
message PartitionToken {
  // Read params from the PartitionRead request in which the partition token was
  // created.
  message ReadParams {
    required string table = 1;
    optional string index = 2;
    repeated string columns = 3;
    required google.spanner.v1.KeySet key_set = 4;
  }

  message QueryParams {
    optional string sql = 1;
    optional google.protobuf.Struct params = 2;
    map<string, google.spanner.v1.Type> param_types = 3;
  }

  oneof params {
    ReadParams read_params = 1;
    QueryParams query_params = 2;
  }

  // Session in which this partition token was created.
  required string session = 3;

  // Id of the transaction in which this partition token was created.
  required bytes transaction_id = 4;

  oneof partition {
    // Internal representation of the partition that should be read.
    google.spanner.v1.KeySet partitioned_key_set = 5;

    // True if query using partition token should return an empty result set.
    bool empty_query_partition = 6;
  }
}