Package com.google.cloud.bigquery.storage.v1

Class BaseBigQueryReadClient

java.lang.Object
com.google.cloud.bigquery.storage.v1.BaseBigQueryReadClient
All Implemented Interfaces:
com.google.api.gax.core.BackgroundResource, AutoCloseable
@Generated("by gapic-generator-java") public class BaseBigQueryReadClient extends Object implements com.google.api.gax.core.BackgroundResource
Service Description: BigQuery Read API.

The Read API can be used to read data from BigQuery.

This class provides the ability to make remote calls to the backing service through method calls that map to API methods. Sample code to get started: 


 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   ProjectName parent = ProjectName.of("[PROJECT]");
   ReadSession readSession = ReadSession.newBuilder().build();
   int maxStreamCount = 940837515;
   ReadSession response =
       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
 }

Note: close() needs to be called on the BaseBigQueryReadClient object to clean up resources such as threads. In the example above, try-with-resources is used, which automatically calls close().

Methods
Method Description Method Variants

CreateReadSession

Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.

A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.

Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.

Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.

Request object method variants only take one parameter, a request object, which must be constructed before the call.

  • createReadSession(CreateReadSessionRequest request)

"Flattened" method variants have converted the fields of the request object into function parameters to enable multiple ways to call the same method.

  • createReadSession(ProjectName parent, ReadSession readSession, int maxStreamCount)

  • createReadSession(String parent, ReadSession readSession, int maxStreamCount)

Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.

  • createReadSessionCallable()

ReadRows

Reads rows from the stream in the format prescribed by the ReadSession. Each response contains one or more table rows, up to a maximum of 100 MiB per response; read requests which attempt to read individual rows larger than 100 MiB will fail.

Each request also returns a set of stream statistics reflecting the current state of the stream.

Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.

  • readRowsCallable()

SplitReadStream

Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are referred to as the primary and the residual streams of the split. The original `ReadStream` can still be read from in the same manner as before. Both of the returned `ReadStream` objects can also be read from, and the rows returned by both child streams will be the same as the rows read from the original stream.

Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`. Concretely, it is guaranteed that for streams original, primary, and residual, that original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read to completion.

Request object method variants only take one parameter, a request object, which must be constructed before the call.

  • splitReadStream(SplitReadStreamRequest request)

Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.

  • splitReadStreamCallable()

See the individual methods for example code.

Many parameters require resource names to be formatted in a particular way. To assist with these names, this class includes a format method for each type of name, and additionally a parse method to extract the individual identifiers contained within names that are returned.

This class can be customized by passing in a custom instance of BaseBigQueryReadSettings to create(). For example:

To customize credentials: 


 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 BaseBigQueryReadSettings baseBigQueryReadSettings =
     BaseBigQueryReadSettings.newBuilder()
         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
         .build();
 BaseBigQueryReadClient baseBigQueryReadClient =
     BaseBigQueryReadClient.create(baseBigQueryReadSettings);

To customize the endpoint: 


 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 BaseBigQueryReadSettings baseBigQueryReadSettings =
     BaseBigQueryReadSettings.newBuilder().setEndpoint(myEndpoint).build();
 BaseBigQueryReadClient baseBigQueryReadClient =
     BaseBigQueryReadClient.create(baseBigQueryReadSettings);

Please refer to the GitHub repository's samples for more quickstart code snippets.

  • Constructor Details

    • BaseBigQueryReadClient

      protected BaseBigQueryReadClient(BaseBigQueryReadSettings settings) throws IOException
      Constructs an instance of BaseBigQueryReadClient, using the given settings. This is protected so that it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
      Throws:
      IOException

    • BaseBigQueryReadClient

      protected BaseBigQueryReadClient(BigQueryReadStub stub)

  • Method Details

    • create

      public static final BaseBigQueryReadClient create() throws IOException
      Constructs an instance of BaseBigQueryReadClient with default settings.
      Throws:
      IOException

    • create

      public static final BaseBigQueryReadClient create(BaseBigQueryReadSettings settings) throws IOException
      Constructs an instance of BaseBigQueryReadClient, using the given settings. The channels are created based on the settings passed in, or defaults for any settings that are not set.
      Throws:
      IOException

    • create

      public static final BaseBigQueryReadClient create(BigQueryReadStub stub)
      Constructs an instance of BaseBigQueryReadClient, using the given stub for making calls. This is for advanced usage - prefer using create(BaseBigQueryReadSettings).

    • getSettings

      public final BaseBigQueryReadSettings getSettings()

    • getStub

      public BigQueryReadStub getStub()

    • createReadSession

      public final ReadSession createReadSession(ProjectName parent, ReadSession readSession, int maxStreamCount)
      Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.

      A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.

      Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.

      Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   ProjectName parent = ProjectName.of("[PROJECT]");
   ReadSession readSession = ReadSession.newBuilder().build();
   int maxStreamCount = 940837515;
   ReadSession response =
       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
 }
      Parameters:
      parent - Required. The request project that owns the session, in the form of `projects/{project_id}`.
      readSession - Required. Session to be created.
      maxStreamCount - 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.

      Throws:
      com.google.api.gax.rpc.ApiException - if the remote call fails

    • createReadSession

      public final ReadSession createReadSession(String parent, ReadSession readSession, int maxStreamCount)
      Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.

      A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.

      Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.

      Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   String parent = ProjectName.of("[PROJECT]").toString();
   ReadSession readSession = ReadSession.newBuilder().build();
   int maxStreamCount = 940837515;
   ReadSession response =
       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
 }
      Parameters:
      parent - Required. The request project that owns the session, in the form of `projects/{project_id}`.
      readSession - Required. Session to be created.
      maxStreamCount - 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.

      Throws:
      com.google.api.gax.rpc.ApiException - if the remote call fails

    • createReadSession

      public final ReadSession createReadSession(CreateReadSessionRequest request)
      Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.

      A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.

      Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.

      Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   CreateReadSessionRequest request =
       CreateReadSessionRequest.newBuilder()
           .setParent(ProjectName.of("[PROJECT]").toString())
           .setReadSession(ReadSession.newBuilder().build())
           .setMaxStreamCount(940837515)
           .setPreferredMinStreamCount(-1905507237)
           .build();
   ReadSession response = baseBigQueryReadClient.createReadSession(request);
 }
      Parameters:
      request - The request object containing all of the parameters for the API call.
      Throws:
      com.google.api.gax.rpc.ApiException - if the remote call fails

    • createReadSessionCallable

      public final com.google.api.gax.rpc.UnaryCallable<CreateReadSessionRequest,ReadSession> createReadSessionCallable()
      Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.

      A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.

      Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.

      Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   CreateReadSessionRequest request =
       CreateReadSessionRequest.newBuilder()
           .setParent(ProjectName.of("[PROJECT]").toString())
           .setReadSession(ReadSession.newBuilder().build())
           .setMaxStreamCount(940837515)
           .setPreferredMinStreamCount(-1905507237)
           .build();
   ApiFuture<ReadSession> future =
       baseBigQueryReadClient.createReadSessionCallable().futureCall(request);
   // Do something.
   ReadSession response = future.get();
 }

    • readRowsCallable

      public final com.google.api.gax.rpc.ServerStreamingCallable<ReadRowsRequest,ReadRowsResponse> readRowsCallable()
      Reads rows from the stream in the format prescribed by the ReadSession. Each response contains one or more table rows, up to a maximum of 100 MiB per response; read requests which attempt to read individual rows larger than 100 MiB will fail.

      Each request also returns a set of stream statistics reflecting the current state of the stream.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   ReadRowsRequest request =
       ReadRowsRequest.newBuilder()
           .setReadStream(
               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
           .setOffset(-1019779949)
           .build();
   ServerStream<ReadRowsResponse> stream =
       baseBigQueryReadClient.readRowsCallable().call(request);
   for (ReadRowsResponse response : stream) {
     // Do something when a response is received.
   }
 }

    • splitReadStream

      public final SplitReadStreamResponse splitReadStream(SplitReadStreamRequest request)
      Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are referred to as the primary and the residual streams of the split. The original `ReadStream` can still be read from in the same manner as before. Both of the returned `ReadStream` objects can also be read from, and the rows returned by both child streams will be the same as the rows read from the original stream.

      Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`. Concretely, it is guaranteed that for streams original, primary, and residual, that original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read to completion.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   SplitReadStreamRequest request =
       SplitReadStreamRequest.newBuilder()
           .setName(
               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
           .setFraction(-1653751294)
           .build();
   SplitReadStreamResponse response = baseBigQueryReadClient.splitReadStream(request);
 }
      Parameters:
      request - The request object containing all of the parameters for the API call.
      Throws:
      com.google.api.gax.rpc.ApiException - if the remote call fails

    • splitReadStreamCallable

      public final com.google.api.gax.rpc.UnaryCallable<SplitReadStreamRequest,SplitReadStreamResponse> splitReadStreamCallable()
      Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are referred to as the primary and the residual streams of the split. The original `ReadStream` can still be read from in the same manner as before. Both of the returned `ReadStream` objects can also be read from, and the rows returned by both child streams will be the same as the rows read from the original stream.

      Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`. Concretely, it is guaranteed that for streams original, primary, and residual, that original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read to completion.

      Sample code: 

      
 // This snippet has been automatically generated and should be regarded as a code template only.
 // It will require modifications to work:
 // - It may require correct/in-range values for request initialization.
 // - It may require specifying regional endpoints when creating the service client as shown in
 // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   SplitReadStreamRequest request =
       SplitReadStreamRequest.newBuilder()
           .setName(
               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
           .setFraction(-1653751294)
           .build();
   ApiFuture<SplitReadStreamResponse> future =
       baseBigQueryReadClient.splitReadStreamCallable().futureCall(request);
   // Do something.
   SplitReadStreamResponse response = future.get();
 }

    • close

      public final void close()
      Specified by:
      close in interface AutoCloseable

    • shutdown

      public void shutdown()
      Specified by:
      shutdown in interface com.google.api.gax.core.BackgroundResource

    • isShutdown

      public boolean isShutdown()
      Specified by:
      isShutdown in interface com.google.api.gax.core.BackgroundResource

    • isTerminated

      public boolean isTerminated()
      Specified by:
      isTerminated in interface com.google.api.gax.core.BackgroundResource

    • shutdownNow

      public void shutdownNow()
      Specified by:
      shutdownNow in interface com.google.api.gax.core.BackgroundResource

    • awaitTermination

      public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException
      Specified by:
      awaitTermination in interface com.google.api.gax.core.BackgroundResource
      Throws:
      InterruptedException