Struct mz_persist_types::stats::StructStats

pub struct StructStats {
    pub len: usize,
    pub cols: BTreeMap<String, Box<dyn DynStats>>,
}

Statistics about a column of a struct type with a uniform schema (the same columns and associated T: Data types in each instance of the struct).

Fields

len: usize

The count of structs in the column.

cols: BTreeMap<String, Box<dyn DynStats>>

Statistics about each of the columns in the struct.

This will often be all of the columns, but it’s not guaranteed. Persist reserves the right to prune statistics about some or all of the columns.

Implementations

impl StructStats

pub fn col<T: Data>(&self, name: &str) -> Result<Option<&T::Stats>, String>

Returns the statistics for the given column in the struct.

This will often be all of the columns, but it’s not guaranteed. Persist reserves the right to prune statistics about some or all of the columns.

Trait Implementations

impl Arbitrary for StructStats

type Parameters = <usize as Arbitrary>::Parameters

The type of parameters that arbitrary_with accepts for configuration of the generated Strategy. Parameters must implement Default.

type Strategy = Map<(<usize as Arbitrary>::Strategy, BoxedStrategy<BTreeMap<String, Box<dyn DynStats>>>), fn(_: (usize, BTreeMap<String, Box<dyn DynStats>>)) -> StructStats>

The type of Strategy used to generate values of type Self.

fn arbitrary_with(_top: Self::Parameters) -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self). The strategy is passed the arguments given in args.

fn arbitrary() -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self).

impl ColumnStats<DynStruct> for StructStats

fn lower<'a>(&'a self) -> Option<<DynStruct as Data>::Ref<'a>>

An inclusive lower bound on the data contained in the column, if known.

fn upper<'a>(&'a self) -> Option<<DynStruct as Data>::Ref<'a>>

Same as Self::lower but an (also inclusive) upper bound.

fn none_count(&self) -> usize

The number of Nones if this column is optional or 0 if it isn’t.

impl Debug for StructStats

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

Formats the value using the given formatter.

impl Default for StructStats

fn default() -> StructStats

Returns the “default value” for a type.

impl DynStats for StructStats

fn as_any(&self) -> &dyn Any

Returns self as a dyn Any for downcasting.

fn into_proto(&self) -> ProtoDynStats

See mz_proto::RustType::into_proto.

fn debug_json(&self) -> Value

Formats these statistics for use in INSPECT SHARD and debugging.

fn type_name(&self) -> &'static str

Returns the name of the erased type for use in error messages.

impl RustType<ProtoStructStats> for StructStats

fn into_proto(&self) -> ProtoStructStats

Convert a Self into a Proto value.

fn from_proto(proto: ProtoStructStats) -> Result<Self, TryFromProtoError>

Consume and convert a Proto back into a Self value.

impl Serialize for StructStats

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

Serialize this value into the given Serde serializer.

impl StatsFrom<DynStructCol> for StructStats

fn stats_from(col: &DynStructCol, validity: ValidityRef) -> Self

Computes statistics from a column of data.