Enum TransientKind 

#[non_exhaustive]
pub enum TransientKind {
    OptimisticConflict,
    SerializationFailure,
    Deadlock,
    PoolTimeout,
    ConnectionLost,
    UpstreamUnavailable,
    Congestion,
    Other,
}

Why a Transient outcome may succeed on retry.

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.

OptimisticConflict

SerializationFailure

Deadlock

PoolTimeout

ConnectionLost

UpstreamUnavailable

Congestion

Other

Implementations

impl TransientKind

pub fn as_str(self) -> &'static str

pub fn is_congestion(self) -> bool

A transient that carries no evidence about the operation itself, only about shared capacity — a retry loop backs off without spending its budget, where a conflict kind (Deadlock, SerializationFailure, OptimisticConflict) is evidence the operation can be re-run at once.

pub fn is_contention(self) -> bool

Postgres aborted the attempt because it lost a race with a concurrent transaction: a deadlock victim (40P01) or a serialization failure (40001). Two things follow that no other transient guarantees. The server confirmed the rollback, so the attempt is safe to re-run even when the failure surfaced at COMMIT, where any other error is ambiguous. And the failure says nothing about the data involved, only about the interleaving, so there is nothing in it to attribute to one row or to bisect for.

OptimisticConflict is deliberately not contention: it is raised above Postgres by a version check and names one stale row, so a batch search can isolate it, and a plain re-run with the same stale state would only conflict again.

pub fn from_sqlstate(code: &str) -> Option<TransientKind>

The one row of the sqlx lane table (sqlx.rs, private) a consumer with a non-sqlx Postgres driver could still want: which TransientKind a Postgres SQLSTATE code maps to, independent of sqlx::Error. Lives here, not behind the sqlx feature, so it is reachable without that dependency.

Trait Implementations

impl Clone for TransientKind

fn clone(&self) -> TransientKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TransientKind

impl Debug for TransientKind

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

Formats the value using the given formatter.

impl Display for TransientKind

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

Formats the value using the given formatter.

impl Eq for TransientKind

impl Hash for TransientKind

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for TransientKind

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TransientKind