Google Cloud Spanner v1 API - Enum TransactionOptions.Types.ReadWrite.Types.ReadLockMode (5.2.0)

public enum TransactionOptions.Types.ReadWrite.Types.ReadLockMode

Reference documentation and code samples for the Google Cloud Spanner v1 API enum TransactionOptions.Types.ReadWrite.Types.ReadLockMode.

ReadLockMode is used to set the read lock mode for read-write transactions.

Namespace

Google.Cloud.Spanner.V1.dll

Fields
Name	Description
`Optimistic`	Optimistic lock mode. 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. Semantics described only applies to [SERIALIZABLE][google.spanner.v1.TransactionOptions.IsolationLevel.SERIALIZABLE] isolation.
`Pessimistic`	Pessimistic lock mode. Read locks are acquired immediately on read. Semantics described only applies to [SERIALIZABLE][google.spanner.v1.TransactionOptions.IsolationLevel.SERIALIZABLE] isolation.
`Unspecified`	Default value. If isolation level is [REPEATABLE_READ][google.spanner.v1.TransactionOptions.IsolationLevel.REPEATABLE_READ], then it is an error to specify `read_lock_mode`. Locking semantics default to `OPTIMISTIC`. No validation checks are done for reads, except to validate that the data that was served at the snapshot time is unchanged at commit time in the following cases: reads done as part of queries that use `SELECT FOR UPDATE` reads done as part of statements with a `LOCK_SCANNED_RANGES` hint reads done as part of DML statements At all other isolation levels, if `read_lock_mode` is the default value, then pessimistic read locks are used.