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

Class BigQueryReadGrpc.BigQueryReadFutureStub

  • Enclosing class:
    BigQueryReadGrpc
    public static final class BigQueryReadGrpc.BigQueryReadFutureStub
extends io.grpc.stub.AbstractFutureStub<BigQueryReadGrpc.BigQueryReadFutureStub>
    A stub to allow clients to do ListenableFuture-style rpc calls to service BigQueryRead. 
     BigQuery Read API.
 The Read API can be used to read data from BigQuery.

    • Method Detail

      • createReadSession

        public com.google.common.util.concurrent.ListenableFuture<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.

      • splitReadStream

        public com.google.common.util.concurrent.ListenableFuture<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.