Field Types

YXDB supports 17 field types. This page documents the Rust API for working with them. For the complete binary encoding reference, see the Field Type Reference.

Summary

YXDB Type	Category	Rust/Arrow Type	Polars Type
Boolean	Boolean	BooleanArray	Boolean
Byte	Integer	Int16Array	Int16
Int16	Integer	Int16Array	Int16
Int32	Integer	Int32Array	Int32
Int64	Integer	Int64Array	Int64
Float	Float	Float32Array	Float32
Double	Float	Float64Array	Float64
FixedDecimal	Decimal	Decimal128Array	Decimal
String	Fixed string	Utf8Array	String
WString	Fixed string	Utf8Array	String
V_String	Variable string	LargeUtf8Array	String
V_WString	Variable string	LargeUtf8Array	String
Date	Temporal	Date32Array	Date
DateTime	Temporal	TimestampArray(us)	Datetime(us)
Time	Temporal	Time64Array(ns)	Time
Blob	Binary	LargeBinaryArray	Binary
SpatialObj	Binary	LargeBinaryArray	Binary

The FieldType Enum

pub enum FieldType {
    Boolean,
    Byte,
    Int16,
    Int32,
    Int64,
    Float,
    Double,
    FixedDecimal,
    String,
    WString,
    V_String,
    V_WString,
    Date,
    DateTime,
    Time,
    Blob,
    SpatialObj,
}

The FieldMeta Struct

pub struct FieldMeta {
    pub name: String,
    pub field_type: FieldType,
    pub size: u32,
    pub scale: u32,
}

• size - Width for fixed-size fields, maximum length for variable-length fields. For FixedDecimal, this is the precision.
• scale - Number of decimal places. Only meaningful for FixedDecimal.

Type Details

Boolean

Binary representation: 1 byte, where 0x00 = false, 0x01 = true, 0x02 = null.

Integer Types (Byte, Int16, Int32, Int64)

Little-endian signed integers followed by a 1-byte null indicator (0x00 = valid, 0x01 = null). Byte is an unsigned 8-bit value stored in an Int16 to accommodate the full 0-255 range.

Float Types (Float, Double)

IEEE 754 floating-point values (4 or 8 bytes) followed by a 1-byte null indicator.

FixedDecimal

ASCII string representation of a decimal number (e.g., "12345.67"), null-padded to size bytes, followed by a null indicator. SigilYX parses this into a Polars Decimal column preserving the original precision and scale.

String Types

Type	Encoding	Length
String	ASCII / Latin-1	Fixed size bytes + null indicator
WString	UTF-16LE	Fixed size * 2 bytes + null indicator
V_String	ASCII / Latin-1	Variable length (4-byte offset in fixed portion)
V_WString	UTF-16LE	Variable length (4-byte offset in fixed portion)

Fixed strings are padded with null bytes. Variable strings use the offset/length encoding described in the specification.

SigilYX converts all strings to UTF-8 on read. For WString and V_WString, an SSE2-accelerated fast path handles the common ASCII-subset case.

Temporal Types

Type	Format	Arrow Type
Date	YYYY-MM-DD (10 chars)	Date32 (days since epoch)
DateTime	YYYY-MM-DD HH:MM:SS (19 chars)	Timestamp(Microsecond)
Time	HH:MM:SS (8 chars)	Time64(Nanosecond)

Temporal values are stored as ASCII strings in the YXDB file and parsed to native Arrow temporal types on read.

Binary Types (Blob, SpatialObj)

Variable-length binary data using the same offset/length encoding as variable strings. SpatialObj contains Alteryx SHP geometry data, which SigilYX can optionally decode to ISO WKB format.