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 2025-04-02 UTC."],[[["This documentation page covers the `ReadLockMode` enum within the Google Cloud Spanner v1 API, which is used to define the read lock mode for read-write transactions."],["The latest version of this `ReadLockMode` documentation is 5.0.0-beta05, with multiple prior versions listed down to 3.5.0."],["There are three distinct read lock modes available: `Optimistic`, `Pessimistic`, and `Unspecified`."],["`Optimistic` locking acquires locks upon commit, while `Pessimistic` locking acquires locks immediately upon read."],["If `ReadLockMode` is left `Unspecified`, it defaults to `Pessimistic` locking behavior."]]],[]]
