Enum mz_adapter::coord::appends::DeferredWriteOp

pub enum DeferredWriteOp {
    Plan(DeferredPlan),
    Write(DeferredWrite),
}

An operation that was deferred waiting for WriteLocks.

Variants

Plan(DeferredPlan)

A plan, e.g. ReadThenWrite, that needs locks before sequencing.

Write(DeferredWrite)

Inserts into a collection.

Implementations

impl DeferredWriteOp

pub(crate) fn can_be_optimistically_retried(&self) -> bool

Certain operations, e.g. “blind writes”/INSERT statements, can be optimistically retried because we can share a write lock between multiple operations. In this case we wait to acquire the locks until group_commit, where writes are groupped by collection and comitted at a single timestamp.

Other operations, e.g. read-then-write plans/UPDATE statements, must uniquely hold their write locks and thus we should acquire the locks in try_deferred to prevent multiple queued plans attempting to get retried at the same time, when we know only one can proceed.

pub fn required_locks(&self) -> impl Iterator<Item = CatalogItemId> + '_

Returns an Iterator of all the required locks for current operation.

pub fn conn_id(&self) -> &ConnectionId

Returns the ConnectionId associated with this deferred op.

pub fn into_ctx(self) -> ExecuteContext

Consumes the DeferredWriteOp, returning the inner ExecuteContext.

Trait Implementations

impl Debug for DeferredWriteOp

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

Formats the value using the given formatter.