Struct partition::range::RangePartitionRule

pub struct RangePartitionRule {
    column_name: String,
    bounds: Vec<Value>,
    regions: Vec<RegionNumber>,
}

RangePartitionRule manages the distribution of partitions partitioning by some column’s value range. It’s generated from create table request, using MySQL’s syntax:

CREATE TABLE table_name (
    columns definition
)
PARTITION BY RANGE (column_name) (
    PARTITION partition_name VALUES LESS THAN (value)[,
    PARTITION partition_name VALUES LESS THAN (value)][,
    ...]
)

Please refer to MySQL’s “RANGE Partitioning” document for more details.

Some partition related validations like:

• the column used in partitioning must be defined in the create table request
• partition name must be unique
• range bounds(the “value“s) must be strictly increased
• the last partition range must be bounded by “MAXVALUE”

are all been done in the create table SQL parsing stage. So we can safely skip some checks on the input arguments.

Important Notes on Partition and Region

Technically, table “partition” is a concept of data sharding logically, i.e., how table’s data are distributed in logic. And “region” is of how data been placed physically. They should be used in different ways.

However, currently we have only one region for each partition. For the sake of simplicity, the terms “partition” and “region” are used interchangeably.

Fields

column_name: String

bounds: Vec<Value>

regions: Vec<RegionNumber>

Implementations

impl RangePartitionRule

pub fn new( column_name: impl Into<String>, bounds: Vec<Value>, regions: Vec<RegionNumber>, ) -> Self

pub fn column_name(&self) -> &String

pub fn all_regions(&self) -> &Vec<RegionNumber>

pub fn bounds(&self) -> &Vec<Value>

Trait Implementations

impl Debug for RangePartitionRule

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for RangePartitionRule

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartitionRule for RangePartitionRule

fn as_any(&self) -> &dyn Any

fn partition_columns(&self) -> Vec<String>

fn find_region(&self, values: &[Value]) -> Result<RegionNumber, Error>

Finds the target region by the partition values.

fn find_regions_by_exprs( &self, exprs: &[PartitionExpr], ) -> Result<Vec<RegionNumber>, Error>

Finds the target regions by the partition expressions.

impl Serialize for RangePartitionRule

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

where __S: Serializer,

Serialize this value into the given Serde serializer.