Struct ColumnDecimal 

pub struct ColumnDecimal { /* private fields */ }

Column for Decimal types with precision and scale Stores values as integers (scaled by 10^scale)

Uses efficient internal representation based on precision:

• precision <= 9: ColumnInt32 (4 bytes per value)
• precision <= 18: ColumnInt64 (8 bytes per value)
• precision > 18: ColumnInt128 (16 bytes per value)

Implementations

impl ColumnDecimal

pub fn new(type_: Type) -> Self

Create a new empty decimal column for the given Decimal type.

Panics

Panics if type_ is not a Type::Decimal.

pub fn with_data(self, data: Vec<i128>) -> Self

Set the column data from a vector of raw scaled i128 values.

pub fn append_from_string(&mut self, s: &str) -> Result<()>

Append a decimal value parsed from a string like "123.45".

Errors

Returns an error if the string is not a valid decimal or the fractional part exceeds the column’s scale.

pub fn append(&mut self, value: i128)

Append decimal from i128 (raw scaled value)

pub fn at(&self, index: usize) -> i128

Get decimal at index as i128 (raw scaled value)

pub fn as_string(&self, index: usize) -> String

Format decimal at index as string

pub fn precision(&self) -> usize

Returns the precision (total number of digits) of this decimal column.

pub fn scale(&self) -> usize

Returns the scale (digits after the decimal point) of this decimal column.

pub fn len(&self) -> usize

Returns the number of values in this column.

pub fn is_empty(&self) -> bool

Returns true if the column contains no values.

Trait Implementations

impl Column for ColumnDecimal

fn column_type(&self) -> &Type

Get the type of this column

fn size(&self) -> usize

Get the number of rows in this column

fn clear(&mut self)

Clear all data from the column

fn reserve(&mut self, new_cap: usize)

Reserve capacity for at least new_cap elements

fn append_column(&mut self, other: ColumnRef) -> Result<()>

Append another column’s data to this column

fn load_from_buffer(&mut self, buffer: &mut &[u8], rows: usize) -> Result<()>

Load column data from byte buffer

fn save_to_buffer(&self, buffer: &mut BytesMut) -> Result<()>

Save column data to byte buffer

fn clone_empty(&self) -> ColumnRef

Create an empty clone of this column (same type, no data)

fn slice(&self, begin: usize, len: usize) -> Result<ColumnRef>

Create a slice of this column

fn as_any(&self) -> &dyn Any

Downcast to a concrete column type

fn as_any_mut(&mut self) -> &mut dyn Any

Downcast to a mutable concrete column type

fn load_prefix(&mut self, _buffer: &mut &[u8], _rows: usize) -> Result<()>

Load column prefix from byte buffer (for types that need prefix data) Default implementation is a no-op. Override for types like LowCardinality. This matches C++ clickhouse-cpp’s LoadPrefix pattern.

fn save_prefix(&self, _buffer: &mut BytesMut) -> Result<()>

Save column prefix to byte buffer (for types that need prefix data) Default implementation is a no-op. Override for types like LowCardinality, Array with special nested types. This matches C++ clickhouse-cpp’s SavePrefix pattern.