Struct Index 

pub struct Index {
    pub id: IndexId,
    pub fields: Vec<IndexField>,
    pub unique: bool,
    pub primary_key: bool,
}

An index defined on a model’s fields.

Indices speed up queries by letting the database locate rows without a full table scan. An index can cover one or more fields, may enforce uniqueness, and may serve as the primary key.

Fields are split into partition fields (used for distribution in NoSQL backends like DynamoDB) and local fields (sort keys or secondary columns).

Examples

use toasty_core::schema::app::{Index, IndexId, IndexField, ModelId};
use toasty_core::schema::db::{IndexOp, IndexScope};

let index = Index {
    id: IndexId { model: ModelId(0), index: 0 },
    fields: vec![IndexField {
        field: ModelId(0).field(0),
        op: IndexOp::Eq,
        scope: IndexScope::Local,
    }],
    unique: true,
    primary_key: true,
};
assert!(index.unique);
assert!(index.primary_key);

Fields

id: IndexId

Uniquely identifies this index within the schema.

fields: Vec<IndexField>

Fields included in the index, in order.

unique: bool

When true, the index enforces uniqueness across indexed entries.

primary_key: bool

When true, this index represents the model’s primary key.

Implementations

impl Index

pub fn partition_fields(&self) -> &[IndexField]

Returns the partition-scoped fields of this index.

Partition fields come before local fields and determine data distribution in NoSQL backends.

pub fn local_fields(&self) -> &[IndexField]

Returns the local (sort-key) fields of this index.

Local fields follow partition fields and determine ordering within a partition.

Trait Implementations

impl Clone for Index

fn clone(&self) -> Index

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Index

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

Formats the value using the given formatter.