Locks for reads within the transaction are not acquired on read.
Instead the locks are acquired on a commit to validate that
read/queried data has not changed since the transaction started.
Pessimistic
Pessimistic lock mode.
Read locks are acquired immediately on read.
Unspecified
Default value.
If the value is not specified, the pessimistic read lock is used.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-21 UTC."],[[["This page provides documentation for the `ReadLockMode` enum within the Google Cloud Spanner v1 API, specifically for read-write transaction options."],["The `ReadLockMode` enum offers three modes: `Optimistic`, which defers locking until commit; `Pessimistic`, which locks immediately upon reading; and `Unspecified`, which defaults to pessimistic locking."],["The page offers access to versioned documentation for this `ReadLockMode` enum ranging from version 3.5.0 up to the latest beta version 5.0.0-beta05."],["Version 4.4.0 is the specific version of the `ReadLockMode` documentation that this page initially focuses on."]]],[]]
