Enum IsolationLevel 

#[non_exhaustive]
pub enum IsolationLevel {
    Unspecified,
    Serializable,
    RepeatableRead,
    UnknownValue(UnknownValue),
}

IsolationLevel is used when setting the isolation level for a transaction.

Working with unknown values

This enum is defined as #[non_exhaustive] because Google Cloud may add additional enum variants at any time. Adding new variants is not considered a breaking change. Applications should write their code in anticipation of:

• New values appearing in future releases of the client library, and
• New values received dynamically, without application changes.

Please consult the Working with enums section in the user guide for some guidelines.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Unspecified

Default value.

If the value is not specified, the SERIALIZABLE isolation level is used.

Serializable

All transactions appear as if they executed in a serial order, even if some of the reads, writes, and other operations of distinct transactions actually occurred in parallel. Spanner assigns commit timestamps that reflect the order of committed transactions to implement this property. Spanner offers a stronger guarantee than serializability called external consistency. For more information, see TrueTime and external consistency.

RepeatableRead

All reads performed during the transaction observe a consistent snapshot of the database, and the transaction is only successfully committed in the absence of conflicts between its updates and any concurrent updates that have occurred since that snapshot. Consequently, in contrast to SERIALIZABLE transactions, only write-write conflicts are detected in snapshot transactions.

This isolation level does not support read-only and partitioned DML transactions.

When REPEATABLE_READ is specified on a read-write transaction, the locking semantics default to OPTIMISTIC.

UnknownValue(UnknownValue)

If set, the enum was initialized with an unknown value.

Applications can examine the value using IsolationLevel::value or IsolationLevel::name.

Implementations

impl IsolationLevel

pub fn value(&self) -> Option<i32>

Gets the enum value.

Returns None if the enum contains an unknown value deserialized from the string representation of enums.

pub fn name(&self) -> Option<&str>

Gets the enum value as a string.

Returns None if the enum contains an unknown value deserialized from the integer representation of enums.

Trait Implementations

impl Clone for IsolationLevel

fn clone(&self) -> IsolationLevel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IsolationLevel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for IsolationLevel

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for IsolationLevel

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for IsolationLevel

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<&str> for IsolationLevel

fn from(value: &str) -> Self

Converts to this type from the input type.

impl From<i32> for IsolationLevel

fn from(value: i32) -> Self

Converts to this type from the input type.

impl PartialEq for IsolationLevel

fn eq(&self, other: &IsolationLevel) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for IsolationLevel

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for IsolationLevel