// Copyright 2021 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 = "proto3";

package google.cloud.datacatalog.v1;

import "google/api/field_behavior.proto";

option cc_enable_arenas = true;
option csharp_namespace = "Google.Cloud.DataCatalog.V1";
option go_package = "google.golang.org/genproto/googleapis/cloud/datacatalog/v1;datacatalog";
option java_multiple_files = true;
option java_package = "com.google.cloud.datacatalog.v1";
option php_namespace = "Google\\Cloud\\DataCatalog\\V1";
option ruby_package = "Google::Cloud::DataCatalog::V1";

// Represents a schema, for example, a BigQuery, GoogleSQL, or Avro schema.
message Schema {
  // The unified GoogleSQL-like schema of columns.
  //
  // The overall maximum number of columns and nested columns is 10,000.
  // The maximum nested depth is 15 levels.
  repeated ColumnSchema columns = 2;
}

// A column within a schema. Columns can be nested inside
// other columns.
message ColumnSchema {
  // Required. Name of the column.
  //
  // Must be a UTF-8 string without dots (.).
  // The maximum size is 64 bytes.
  string column = 6 [(google.api.field_behavior) = REQUIRED];

  // Required. Type of the column.
  //
  // Must be a UTF-8 string with the maximum size of 128 bytes.
  string type = 1 [(google.api.field_behavior) = REQUIRED];

  // Optional. Description of the column. Default value is an empty string.
  //
  // The description must be a UTF-8 string with the maximum size of 2000
  // bytes.
  string description = 2 [(google.api.field_behavior) = OPTIONAL];

  // Optional. A column's mode indicates whether values in this column are required,
  // nullable, or repeated.
  //
  // Only `NULLABLE`, `REQUIRED`, and `REPEATED` values are supported.
  // Default mode is `NULLABLE`.
  string mode = 3 [(google.api.field_behavior) = OPTIONAL];

  // Optional. Schema of sub-columns. A column can have zero or more sub-columns.
  repeated ColumnSchema subcolumns = 7 [(google.api.field_behavior) = OPTIONAL];
}
