Data types

Name	Description	Length constraints
INTEGER	Signed 64-bit integer value. Usually referred to as BIGINT in other databases.	-
BOOLEAN	A boolean value, either TRUE or FALSE	-
VARCHAR	UTF8-encoded text	Maximum number of bytes in the UTF-8 encoded representation of the string
BLOB	Sequence of bytes	Maximum number of bytes in the sequence
TIMESTAMP	Datetime value with microsecond precision	-
FLOAT	IEEE-754 64-bit floating-point number	-
UUID	Universally Unique Identifier (UUID), 128-bit value	-
JSON	RFC 8259 textual JSON data	Maximum number of bytes in the textual representation of the data

Size constraints

Size constraint is specified with a [MAX_SIZE] suffix on the type, e.g. BLOB[16] represents a sequence of up to 16 bytes.

NULL values

NULL values in immudb are not unique - two NULL values are considered equal on comparisons.

Timestamp values

Timestamp values are internally stored as a 64-bit signed integer being a number of microseconds since the epoch time. Those values are not associated with any timezone, whenever a conversion is needed, it is considered to be in UTC.

JSON primitive types and internal SQL types

Except for lists and objects, each JSON type is backed by a specific immudb internal SQL type. The mapping between JSON primitive types and SQL internal types is reported in the following table:

JSON primitive type	Internal SQL type	Description
STRING	VARCHAR	control characters, quotation marks and backslashes must be escaped
NUMBER	FLOAT	NaN, Infinity and -Infinity are not supported
BOOLEAN	BOOLEAN	only lowercase true and false are valid
NULL	NULL	-