Struct mz_compute::compute_state::IndexPeek

pub struct IndexPeek {
    peek: Peek,
    trace_bundle: TraceBundle,
    span: Span,
}

An in-progress index-backed peek, and data to eventually fulfill it.

Fields

peek: Peek

trace_bundle: TraceBundle

The data from which the trace derives.

span: Span

The tracing::Span tracking this peek’s operation

Implementations

impl IndexPeek

fn seek_fulfillment( &mut self, upper: &mut Antichain<Timestamp>, max_result_size: u64, ) -> Option<PeekResponse>

Attempts to fulfill the peek and reports success.

To produce output at peek.timestamp, we must be certain that it is no longer changing. A trace guarantees that all future changes will be greater than or equal to an element of upper.

If an element of upper is less or equal to peek.timestamp, then there can be further updates that would change the output. If no element of upper is less or equal to peek.timestamp, then for any time t less or equal to peek.timestamp it is not the case that upper is less or equal to that timestamp, and so the result cannot further evolve.

fn collect_finished_data( &mut self, max_result_size: u64, ) -> Result<Vec<(Row, NonZeroUsize)>, String>

Collects data for a known-complete peek from the ok stream.

fn dispatch_collect_ok_finished_data( &mut self, max_result_size: u64, ) -> Result<Vec<(Row, NonZeroUsize)>, String>

Dispatches peek finishing of data in the ok stream according to arrangement key-value types.

fn collect_ok_finished_data<Tr>( peek: &mut Peek<Timestamp>, oks_handle: &mut Tr, max_result_size: u64, ) -> Result<Vec<(Row, NonZeroUsize)>, String>

where for<'a> Tr: TraceReader<DiffGat<'a> = &'a Diff>, for<'a> Tr::Key<'a>: ToDatumIter + IntoOwned<'a, Owned = Row> + Eq, for<'a> Tr::Val<'a>: ToDatumIter, for<'a> Tr::TimeGat<'a>: PartialOrder<Timestamp>,

Collects data for a known-complete peek from the ok stream.