Data Types

MuduDB stores values as typed objects. The SQL parser maps SQL type names to internal scalar kinds. Each type has a fixed or variable in-memory representation and well-defined comparison and serialization behaviour.

Overview

Types are divided into scalar and complex categories:

• Scalar — single atomic values (numbers, strings, temporal values).

• Complex — ARRAY, RECORD, and BINARY.

All scalar types support ordering and equality comparison. Complex types have structural comparison rules.

The following table summarises the SQL type names recognised by the parser and their internal mappings.

SQL Type	Internal Kind	Notes
INT	I32	32-bit signed integer
BIGINT	I64	64-bit signed integer
HUGEINT	I128	128-bit signed integer
FLOAT, REAL	F32	32-bit IEEE-754 float
DOUBLE	F64	64-bit IEEE-754 float
NUMERIC(p,s)	Numeric	Arbitrary-precision decimal
DECIMAL(p,s)	Numeric	Alias for NUMERIC
CHAR(n)	String	Fixed-length string (padded)
VARCHAR(n)	String	Variable-length string
TEXT	String	Unbounded text
DATE	Date	Calendar date
TIME(p)	Time	Time of day with optional fractional-second precision
TIMESTAMP(p)	Timestamp	Date+time without time zone
TIMESTAMPTZ(p)	TimestampTz	Date+time with time zone
ARRAY	Array	Ordered collection of elements
RECORD	Record	Structured object with named fields
BINARY	Binary	Raw byte sequence

• Integer Types
• Floating-Point Types
• Fixed-Point Types
• String Types
• Temporal Types
• Other Types

Nullability

Every column is nullable by default unless declared NOT NULL or marked as part of a PRIMARY KEY. NULL is a valid literal in INSERT and UPDATE statements.

CREATE TABLE example (
    id   INT PRIMARY KEY,        -- implicitly NOT NULL
    name CHAR(32) NOT NULL,      -- explicitly NOT NULL
    note VARCHAR(200)            -- nullable by default
);

Unsupported Types

The following types are recognised by the grammar but not yet implemented in the SQL parser:

• BOOLEAN

• INTEGER (use INT instead)

• SMALLINT

• TINYINT

Additionally, the internal type U128 (OID) has no SQL keyword mapping in v0.1.

Attempting to create a column with any unsupported type results in a “not yet implemented” error.