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.
Constructors
Transaction(ReadOnlyOptions)
Construction of read-only and read-write transactions.
Parameter
Name
Description
opts
ReadOnlyOptions
Transaction(ReadWriteOptions)
Construction of read-only and read-write transactions.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-22 UTC."],[[["\u003cp\u003eThis document outlines the \u003ccode\u003eTransaction\u003c/code\u003e class within the Google Cloud Spanner C++ client library, providing documentation for versions ranging from 2.11.0 to 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eA \u003ccode\u003eTransaction\u003c/code\u003e object represents a set of atomic reads and writes in a Cloud Spanner database, grouped within the same session and allowing only one active transaction at any given moment.\u003c/p\u003e\n"],["\u003cp\u003eSpanner supports three transaction modes: \u003ccode\u003eReadOnly\u003c/code\u003e (consistent reads without writes), \u003ccode\u003eReadWrite\u003c/code\u003e (reading and writing data), and \u003ccode\u003eSingleUse\u003c/code\u003e (a \u003ccode\u003eReadOnly\u003c/code\u003e transaction where Spanner selects the read timestamp).\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eTransaction\u003c/code\u003e objects are lazily evaluated, meaning no RPCs are initiated during the creation of the object; instead, the first server request, such as \u003ccode\u003eExecuteQuery()\u003c/code\u003e, creates the transaction.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eTransaction\u003c/code\u003e class supports multiple constructors for \u003ccode\u003eReadOnlyOptions\u003c/code\u003e and \u003ccode\u003eReadWriteOptions\u003c/code\u003e and is a regular value type, supporting copy, assign, and move operations.\u003c/p\u003e\n"]]],[],null,[]]
