Data Types

A column’s type defines how its values are represented and which conversions are required when writing data. SQL spellings are not always distinct types: several names below map to the same internal representation.

Supported Types

Type	Accepted aliases	Representation
INTEGER	INT, BIGINT, SMALLINT, TINYINT	Signed 64-bit integer
FLOAT	DOUBLE, REAL	64-bit floating point
DECIMAL	NUMERIC	Exact decimal with precision and scale
TEXT	VARCHAR, CHAR, STRING, CLOB	UTF-8 text
BOOLEAN	BOOL	True or false
TIMESTAMP	DATETIME, TIME	Timestamp value, not a separate time-of-day type
DATE		Calendar date
UUID		16-byte identifier
BYTES	BLOB, BINARY, VARBINARY	Raw bytes
JSON	JSONB	JSON value
VECTOR		Vector value

NULL denotes the absence of a value. A nullable column can contain NULL regardless of its declared type. NULL is not a substitute for a column’s application type.

External types

A trusted native extension can add a catalog-bound scalar type with CREATE TYPE ... FROM EXTENSION. The package descriptor defines a stable object ID, fixed or variable storage shape, canonical codec revision, maximum payload and optional equality, hash and ordering semantics. The SQL name is a schema alias for that identity and can be renamed without changing stored bytes.

External values travel through protocol 17 with their type object ID and codec revision. They do not fall back to BYTES, and the generic ORM does not decode them without a plugin-aware adapter. The Rust SDK 1.2 also has no generic SQL literal input/output callback, so value construction normally uses a native function or typed client adapter. See Native extension commands and Developing native extensions.

Integers, Text and Booleans

SMALLINT and TINYINT do not impose 16-bit or 8-bit bounds. They are aliases of INTEGER. Use a constraint when an application requires a narrower range.

CREATE TABLE typed_values (id SMALLINT, label TEXT, active BOOL);
INSERT INTO typed_values VALUES (100000, 'ready', TRUE);
SELECT id, label, active FROM typed_values;

The row contains 100000, ready and true. INTEGER ranges from -9223372036854775808 to 9223372036854775807. FLOAT is approximate and should not be confused with exact decimal representation.

Use TEXT or a bare text alias such as VARCHAR. Length modifiers such as VARCHAR(255) and CHAR(10) are rejected in this version. They are not accepted as silently ignored length constraints. The same rule rejects type modifiers for types other than DECIMAL/NUMERIC and VECTOR.

Decimals

DECIMAL(p,s) specifies total precision and scale. Precision is between 1 and 38, and scale must not exceed precision. DECIMAL(p) uses scale zero. Bare DECIMAL is accepted without a declared precision/scale constraint.

CREATE TABLE prices (amount DECIMAL(6,2));
INSERT INTO prices VALUES (12.34);
SELECT CAST(amount AS TEXT) AS amount FROM prices;

The result is 12.34. Exact storage is not a promise that every mixed-type arithmetic expression follows another database’s rounding rules. Use typed client parameters for exact values, and check the conversion and arithmetic contract of the operation you need.

Dates, Identifiers and Bytes

DATE represents a calendar day; TIMESTAMP, DATETIME and TIME share timestamp storage. Do not treat the TIME alias as a separate SQL time-only type. UUID has a typed representation rather than being an arbitrary text column. BYTES stores binary values without requiring valid UTF-8.

SELECT CAST('2026-09-08' AS DATE) AS day,
       CAST('01940000-0020-7000-8000-000000000001' AS UUID) AS id,
       FROM_HEX('00ff7f') AS bytes;

The returned values are a date, the specified UUID and three bytes 00 ff 7f. Their display depends on the client. In CLI JSON output, DATE includes days_since_unix_epoch, and BYTES includes raw_hex; not every typed cell uses a scalar value field. Malformed hexadecimal input is rejected.

JSON and Vectors

JSONB is an alias of JSON; the spelling does not imply PostgreSQL JSONB operators or its on-disk format. Likewise, declaring VECTOR does not establish the semantics of every vector function or index.

VECTOR(n) records a dimension between 1 and 65535. Dimensions outside this range are rejected. Index and function contracts are separate from type-name recognition and must be checked for the operations used by an application.

Conversion and Constraints

Use CAST(expression AS type) for an explicit conversion. Assigning a value to a typed column may also require conversion. An invalid conversion should not be treated as equivalent to a missing value; handle the error returned by the operation. NOT NULL, keys and other constraints are separate from type selection.

Continue with expressions for arithmetic, comparisons and NULL.