Enum SchemaChange 

pub enum SchemaChange {
    AddColumn {
        field: FieldRef,
        after: Option<ColumnPath>,
    },
    DropColumn {
        path: ColumnPath,
    },
    RenameColumn {
        path: ColumnPath,
        name: String,
    },
    SetNullable {
        path: ColumnPath,
    },
    WidenType {
        path: ColumnPath,
        data_type: DataType,
    },
    MoveColumn {
        path: ColumnPath,
        after: Option<ColumnPath>,
    },
}

One change to a table’s schema. Changes write metadata only, and older versions keep their schema. Arbor’s rules apply: an added column or field is nullable, NOT NULL may relax but not tighten, numbers widen only without loss, and partition and sort source fields cannot be dropped.

Variants

AddColumn

Add a nullable field after the column or field after, or last when absent.

Fields

field: FieldRef

after: Option<ColumnPath>

DropColumn

Drop the column or field at path.

Fields

path: ColumnPath

RenameColumn

Rename the column or field at path to name, keeping its values.

Fields

path: ColumnPath

name: String

SetNullable

Let the column or field at path hold nulls.

Fields

path: ColumnPath

WidenType

Change the type of the column or field at path to data_type, converting without loss, such as int32 to int64.

Fields

path: ColumnPath

data_type: DataType

MoveColumn

Move the column or field at path after after, or first when absent.

Fields

path: ColumnPath

after: Option<ColumnPath>

Trait Implementations

impl Clone for SchemaChange

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SchemaChange

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

Formats the value using the given formatter.

impl Eq for SchemaChange

impl PartialEq for SchemaChange

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SchemaChange