Struct ColumnStats 

pub struct ColumnStats {
    pub name: String,
    pub null_count: u64,
    pub distinct_count: u64,
    pub distinct_values: u64,
    pub min_value: Option<String>,
    pub max_value: Option<String>,
    pub avg_size_bytes: u64,
    pub histogram: Option<Histogram>,
}

Statistics for a single column.

Fields

name: String

Column name

null_count: u64

Number of null values

distinct_count: u64

Number of distinct values (cardinality)

distinct_values: u64

Number of distinct values (CBO alias).

min_value: Option<String>

Minimum value (serialized)

max_value: Option<String>

Maximum value (serialized)

avg_size_bytes: u64

Average value size in bytes

histogram: Option<Histogram>

Optional histogram for selectivity estimates.

Implementations

impl ColumnStats

pub fn new(name: impl Into<String>) -> Self

Creates new column stats

pub fn with_distinct_count(self, count: u64) -> Self

Sets cardinality

pub fn with_null_count(self, count: u64) -> Self

Sets null count

Trait Implementations

impl Clone for ColumnStats

fn clone(&self) -> ColumnStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnStats

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

Formats the value using the given formatter.

impl Default for ColumnStats

fn default() -> ColumnStats

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ColumnStats

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ColumnStats

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

where __S: Serializer,

Serialize this value into the given Serde serializer.