Struct ColumnStatistics 

pub struct ColumnStatistics {
    pub name: String,
    pub column_type: String,
    pub value_count: u64,
    pub null_count: u64,
    pub min_value: Option<Vec<u8>>,
    pub max_value: Option<Vec<u8>>,
    pub avg_size: f64,
    pub cardinality: u64,
    pub value_histogram: Vec<ValueFrequency>,
    pub has_index: bool,
}

Per-column statistics for query optimization

Fields

name: String

Column name

column_type: String

Column type (CQL type)

value_count: u64

Number of non-null values

null_count: u64

Number of null values

min_value: Option<Vec<u8>>

Minimum value (serialized as bytes)

max_value: Option<Vec<u8>>

Maximum value (serialized as bytes)

avg_size: f64

Average serialized size in bytes

cardinality: u64

Estimated cardinality (distinct values)

value_histogram: Vec<ValueFrequency>

Value frequency histogram for common values

has_index: bool

Whether this column has an index

Trait Implementations

impl Clone for ColumnStatistics

fn clone(&self) -> ColumnStatistics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnStatistics

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ColumnStatistics

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ColumnStatistics

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

where __S: Serializer,

Serialize this value into the given Serde serializer.