Enum mz_repr::explain::IndexUsageType

pub enum IndexUsageType {
    FullScan,
    DifferentialJoin,
    DeltaJoin(DeltaJoinIndexUsageType),
    Lookup(GlobalId),
    PlanRootNoArrangement,
    SinkExport,
    IndexExport,
    FastPathLimit,
    DanglingArrangeBy,
    Unknown,
}

Variants

FullScan

Read the entire index.

DifferentialJoin

Differential join. The work is proportional to the number of matches.

DeltaJoin(DeltaJoinIndexUsageType)

Delta join

Lookup(GlobalId)

IndexedFilter, e.g., something like WHERE x = 42 with an index on x. This also stores the id of the index that we want to do the lookup from. (This id is already chosen by LiteralConstraints, and then IndexUsageType::Lookup communicates this inside CollectIndexRequests from the IndexedFilter to the Get.)

PlanRootNoArrangement

This is a rare case that happens when the user creates an index that is identical to an existing one (i.e., on the same object, and with the same keys). We’ll re-use the arrangement of the existing index. The plan is an ArrangeBy + Get, where the ArrangeBy is requesting the same key as an already existing index. (export_index is what inserts this ArrangeBy.)

SinkExport

The index is used for directly writing to a sink. Can happen with a SUBSCRIBE to an indexed view.

IndexExport

The index is used for creating a new index. Note that either a FullScan or a PlanRootNoArrangement usage will always accompany an IndexExport usage.

FastPathLimit

When a fast path peek has a LIMIT, but no ORDER BY, then we read from the index only as many records (approximately), as the OFFSET + LIMIT needs. Note: When a fast path peek does a lookup and also has a limit, the usage type will be Lookup. However, the smart limiting logic will still apply.

DanglingArrangeBy

We saw a dangling ArrangeBy, i.e., where we have no idea what the arrangement will be used for. This is an internal error. Can be a bug either in CollectIndexRequests, or some other transform that messed up the plan. It’s also possible that somebody is trying to add an ArrangeBy marking for some operator other than a Join. (Which is fine, but please update CollectIndexRequests.)

Unknown

Internal error in CollectIndexRequests or a failed attempt to look up an index in DataflowMetainfo::used_indexes.

Implementations

impl IndexUsageType

pub fn display_vec<'a, I>(usage_types: I) -> impl Display + Sized + 'a

where I: IntoIterator<Item = &'a IndexUsageType>,

Trait Implementations

impl Arbitrary for IndexUsageType

type Parameters = (<DeltaJoinIndexUsageType as Arbitrary>::Parameters, <GlobalId as Arbitrary>::Parameters)

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

type Strategy = Union<BoxedStrategy<IndexUsageType>>

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 Clone for IndexUsageType

fn clone(&self) -> IndexUsageType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for IndexUsageType

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for IndexUsageType

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for IndexUsageType

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

Formats the value using the given formatter.

impl Hash for IndexUsageType

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

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 Ord for IndexUsageType

fn cmp(&self, other: &IndexUsageType) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for IndexUsageType

fn eq(&self, other: &IndexUsageType) -> 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 PartialOrd for IndexUsageType

fn partial_cmp(&self, other: &IndexUsageType) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for IndexUsageType

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 IndexUsageType

impl StructuralPartialEq for IndexUsageType