google::cloud::spanner::Transaction Class Reference

The representation of a Cloud Spanner transaction. More...

#include <google/cloud/spanner/transaction.h>

Classes
class	ReadOnlyOptions
	Options for ReadOnly transactions. More...
class	ReadWriteOptions
	Options for ReadWrite transactions. More...
class	SingleUseOptions
	Options for "single-use", ReadOnly transactions, where Spanner chooses the read timestamp, subject to user-provided bounds. More...

Public Member Functions
	~Transaction ()
Construction of read-only and read-write transactions.
	Transaction (ReadOnlyOptions opts)
	Transaction (ReadWriteOptions opts)
	Transaction (Transaction const &txn, ReadWriteOptions opts)
Regular value type, supporting copy, assign, move.
	Transaction (Transaction &&)=default
Transaction &	operator= (Transaction &&)=default
	Transaction (Transaction const &)=default
Transaction &	operator= (Transaction const &)=default

Friends
Equality operators
bool	operator== (Transaction const &a, Transaction const &b)
bool	operator!= (Transaction const &a, Transaction const &b)

Detailed Description

The representation of a Cloud Spanner transaction.

A transaction is a set of reads and writes that execute atomically at a single logical point in time across the columns/rows/tables in a database. Those reads and writes are grouped by passing them the same Transaction.

All reads/writes in the transaction must be executed within the same session, and that session may have only one transaction active at a time.

Spanner supports these transaction modes:

• ReadOnly. Provides guaranteed consistency across several reads, but does not allow writes. Can be configured to read at timestamps in the past. Does not need to be committed and does not take locks.
• ReadWrite. Supports reading and writing data at a single point in time. Uses pessimistic locking and, if necessary, two-phase commit. May abort, requiring the application to rerun.
• SingleUse. A restricted form of a ReadOnly transaction where Spanner chooses the read timestamp.

Constructor & Destructor Documentation

Transaction() [1/5]

google::cloud::spanner::Transaction::Transaction ( ReadOnlyOptions  opts )

explicit

Note

This is a lazy evaluated operation. No RPCs are made as part of creating a Transaction object. Instead, the first request to the server (for example as part of a ExecuteQuery() call) will also create the transaction.

Transaction() [2/5]

google::cloud::spanner::Transaction::Transaction ( ReadWriteOptions  opts )

explicit

Note

This is a lazy evaluated operation. No RPCs are made as part of creating a Transaction object. Instead, the first request to the server (for example as part of a ExecuteQuery() call) will also create the transaction.

Transaction() [3/5]

google::cloud::spanner::Transaction::Transaction	(	Transaction const &	txn,
		ReadWriteOptions	opts
	)

Note

This is a lazy evaluated operation. No RPCs are made as part of creating a Transaction object. Instead, the first request to the server (for example as part of a ExecuteQuery() call) will also create the transaction.

~Transaction()

google::cloud::spanner::Transaction::~Transaction

(

)

Transaction() [4/5]

google::cloud::spanner::Transaction::Transaction ( Transaction &&  )

default

Transaction() [5/5]

google::cloud::spanner::Transaction::Transaction ( Transaction const &  )

default

Member Function Documentation

operator=() [1/2]

Transaction & google::cloud::spanner::Transaction::operator= ( Transaction &&  )

default

operator=() [2/2]

Transaction & google::cloud::spanner::Transaction::operator= ( Transaction const &  )

default

Friends And Related Function Documentation

operator!=

bool operator!= ( Transaction const &  a, Transaction const &  b  )

friend

operator==

bool operator== ( Transaction const &  a, Transaction const &  b  )

friend