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Migrating BigQuery Storage API from v1beta1 to v1: Java

This guide shows how to migrate Java code using the BigQuery Storage API from version v1beta1 to v1.

Key Changes

  • Service Client: BigQueryStorageClient is replaced by BigQueryReadClient.
  • Table Reference: TableReference proto message is replaced by a simple string representation of the table path in ReadSession.
  • Session Configuration: Several fields from CreateReadSessionRequest have moved into ReadSession (which is now passed as a field in the request).
  • Parallelism: requested_streams is replaced by max_stream_count.
  • Sharding Strategy: sharding_strategy is removed. The server now automatically balances the streams.
  • Read Rows Request: StreamPosition is flattened. You now pass the stream name directly as read_stream and the offset as a top-level field in ReadRowsRequest.

Code Comparison

1. Client Initialization

v1beta1:

import com.google.cloud.bigquery.storage.v1beta1.BigQueryStorageClient;

try (BigQueryStorageClient client = BigQueryStorageClient.create()) {
  // use client
}

v1:

import com.google.cloud.bigquery.storage.v1.BigQueryReadClient;

try (BigQueryReadClient client = BigQueryReadClient.create()) {
  // use client
}

2. Creating a Read Session

v1beta1:

import com.google.cloud.bigquery.storage.v1beta1.BigQueryStorageClient;
import com.google.cloud.bigquery.storage.v1beta1.Storage.CreateReadSessionRequest;
import com.google.cloud.bigquery.storage.v1beta1.Storage.DataFormat;
import com.google.cloud.bigquery.storage.v1beta1.Storage.ReadSession;
import com.google.cloud.bigquery.storage.v1beta1.Storage.ShardingStrategy;
import com.google.cloud.bigquery.storage.v1beta1.ReadOptions.TableReadOptions;
import com.google.cloud.bigquery.storage.v1beta1.TableReferenceProto.TableReference;

// ...

TableReference tableReference = TableReference.newBuilder()
    .setProjectId("bigquery-public-data")
    .setDatasetId("usa_names")
    .setTableId("usa_1910_current")
    .build();

TableReadOptions options = TableReadOptions.newBuilder()
    .addSelectedFields("name")
    .setRowRestriction("state = \"WA\"")
    .build();

CreateReadSessionRequest request = CreateReadSessionRequest.newBuilder()
    .setParent("projects/read-session-project")
    .setTableReference(tableReference)
    .setReadOptions(options)
    .setRequestedStreams(1)
    .setFormat(DataFormat.AVRO)
    .setShardingStrategy(ShardingStrategy.LIQUID)
    .build();

ReadSession session = client.createReadSession(request);

v1:

import com.google.cloud.bigquery.storage.v1.BigQueryReadClient;
import com.google.cloud.bigquery.storage.v1.CreateReadSessionRequest;
import com.google.cloud.bigquery.storage.v1.DataFormat;
import com.google.cloud.bigquery.storage.v1.ReadSession;
import com.google.cloud.bigquery.storage.v1.ReadSession.TableReadOptions;

// ...

// Table path is now a string: projects/{project}/datasets/{dataset}/tables/{table}
String tablePath = "projects/bigquery-public-data/datasets/usa_names/tables/usa_1910_current";

TableReadOptions options = TableReadOptions.newBuilder()
    .addSelectedFields("name")
    .setRowRestriction("state = \"WA\"")
    .build();

// ReadSession holds the session configuration (table, options, format)
ReadSession readSession = ReadSession.newBuilder()
    .setTable(tablePath)
    .setDataFormat(DataFormat.AVRO) // format renamed to data_format
    .setReadOptions(options)
    .build();

CreateReadSessionRequest request = CreateReadSessionRequest.newBuilder()
    .setParent("projects/read-session-project")
    .setReadSession(readSession)
    .setMaxStreamCount(1) // requested_streams renamed to max_stream_count
    .build();

ReadSession session = client.createReadSession(request);

3. Reading Rows

v1beta1:

import com.google.api.gax.rpc.ServerStream;
import com.google.cloud.bigquery.storage.v1beta1.Storage.ReadRowsRequest;
import com.google.cloud.bigquery.storage.v1beta1.Storage.ReadRowsResponse;
import com.google.cloud.bigquery.storage.v1beta1.Storage.StreamPosition;

// ...
StreamPosition readPosition = StreamPosition.newBuilder()
    .setStream(session.getStreams(0)) // Stream object
    .setOffset(0)
    .build();

ReadRowsRequest readRowsRequest = ReadRowsRequest.newBuilder()
    .setReadPosition(readPosition)
    .build();

ServerStream<ReadRowsResponse> stream = client.readRowsCallable().call(readRowsRequest);
for (ReadRowsResponse response : stream) {
  // Process response.getAvroRows()
}

v1:

import com.google.api.gax.rpc.ServerStream;
import com.google.cloud.bigquery.storage.v1.ReadRowsRequest;
import com.google.cloud.bigquery.storage.v1.ReadRowsResponse;

// ...
// ReadRowsRequest is flattened. We pass the stream name (string) and offset directly.
ReadRowsRequest readRowsRequest = ReadRowsRequest.newBuilder()
    .setReadStream(session.getStreams(0).getName()) // Stream name string
    .setOffset(0)
    .build();

ServerStream<ReadRowsResponse> stream = client.readRowsCallable().call(readRowsRequest);
for (ReadRowsResponse response : stream) {
  // Process response.getAvroRows()
  // Note: Prefer using response.getRowCount() over response.getAvroRows().getRowCount() (deprecated)
}