public interface BatchClient
BatchClient
is useful when one wants to read or query a large amount of data from
Cloud Spanner across multiple processes, even across different machines. It allows to create
partitions of Cloud Spanner database and then read or query over each partition independently yet
at the same snapshot.
Modifier and Type | Method and Description |
---|---|
BatchReadOnlyTransaction |
batchReadOnlyTransaction(BatchTransactionId batchTransactionId)
Returns a
BatchReadOnlyTransaction context in which multiple reads and/or queries can
be performed. |
BatchReadOnlyTransaction |
batchReadOnlyTransaction(TimestampBound bound)
Returns a
BatchReadOnlyTransaction context in which multiple reads and/or queries can
be performed. |
BatchReadOnlyTransaction batchReadOnlyTransaction(TimestampBound bound)
BatchReadOnlyTransaction
context in which multiple reads and/or queries can
be performed. All reads/queries will use the same timestamp, and the timestamp can be inspected
after this transaction is created successfully. This is a blocking method since it waits to
finish the rpcs.
Note that the bounded staleness modes, TimestampBound.Mode.MIN_READ_TIMESTAMP
and
TimestampBound.Mode.MAX_STALENESS
, are not supported for BatchReadOnlyTransaction
.
bound
- the timestamp bound at which to perform the read
BatchReadOnlyTransaction txn = batchClient.batchReadOnlyTransaction(TimestampBound.strong());
BatchReadOnlyTransaction batchReadOnlyTransaction(BatchTransactionId batchTransactionId)
BatchReadOnlyTransaction
context in which multiple reads and/or queries can
be performed. This is a non-blocking method. All reads/queries will use the same timestamp, and
the timestamp can be inspected after this transaction is created successfully.
This method is useful to recreate a BatchReadOnlyTransaction object from an existing batchTransactionId. For example one might send the transaction id to a different process or machine and recreate the transaction object there.
batchTransactionId
- to re-initialize the transaction, re-using the timestamp for
successive read/query.Copyright © 2019 Google LLC. All rights reserved.