Enum RecyclingMethod

pub enum RecyclingMethod {
    Fast,
    Verified,
    Clean,
    Custom(String),
}

Possible methods of how a connection is recycled.

The default is Fast which does not check the connection health or perform any clean-up queries.

Variants

Fast

Only run Client::is_closed() when recycling existing connections.

Unless you have special needs this is a safe choice.

Verified

Run Client::is_closed() and execute a test query.

This is slower, but guarantees that the database connection is ready to be used. Normally, Client::is_closed() should be enough to filter out bad connections, but under some circumstances (i.e. hard-closed network connections) it’s possible that Client::is_closed() returns false while the connection is dead. You will receive an error on your first query then.

Clean

Like Verified query method, but instead use the following sequence of statements which guarantees a pristine connection:

CLOSE ALL;
SET SESSION AUTHORIZATION DEFAULT;
RESET ALL;
UNLISTEN *;
SELECT pg_advisory_unlock_all();
DISCARD TEMP;
DISCARD SEQUENCES;

This is similar to calling DISCARD ALL. but doesn’t call DEALLOCATE ALL and DISCARD PLAN, so that the statement cache is not rendered ineffective.

Custom(String)

Like Verified but allows to specify a custom SQL to be executed.

Implementations

impl RecyclingMethod

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

Returns SQL query to be executed when recycling a connection.

Trait Implementations

impl Clone for RecyclingMethod

fn clone(&self) -> RecyclingMethod

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RecyclingMethod

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

Formats the value using the given formatter.

impl Default for RecyclingMethod

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for RecyclingMethod

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for RecyclingMethod

fn eq(&self, other: &RecyclingMethod) -> 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 RecyclingMethod

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for RecyclingMethod

impl StructuralPartialEq for RecyclingMethod