DuckLake specifies multiple different data types for field values, and also supports nested types.
The types of columns are defined in the column_type field of the ducklake_column table.
Primitive Types
| Type | Description |
|---|---|
boolean |
True or false |
int8 |
8-bit signed integer |
int16 |
16-bit signed integer |
int32 |
32-bit signed integer |
int64 |
64-bit signed integer |
uint8 |
8-bit unsigned integer |
uint16 |
16-bit unsigned integer |
uint32 |
32-bit unsigned integer |
uint64 |
64-bit unsigned integer |
float32 |
32-bit IEEE 754 floating-point value |
float64 |
64-bit IEEE 754 floating-point value |
decimal(P, S) |
Fixed-point decimal with precision P and scale S |
time |
Time of day, microsecond precision |
timetz |
Time of day, microsecond precision, with time zone |
date |
Calendar date |
timestamp |
Timestamp, microsecond precision |
timestamptz |
Timestamp, microsecond precision, with time zone |
timestamp_s |
Timestamp, second precision |
timestamp_ms |
Timestamp, microsecond precision |
timestamp_ns |
Timestamp, nanosecond precision |
interval |
Time interval in three different granularities: months, days, and milliseconds |
varchar |
Text |
blob |
Binary data |
json |
JSON |
uuid |
Universally unique identifier |
Nested Types
DuckLake supports nested types and primitive types. Nested types are defined recursively, i.e.,
in order to define a column of type INT[] two columns are defined. The top-level column is of type list, which has a child column of type int32.
The following nested types are supported:
| Type | Description |
|---|---|
list |
Collection of values with a single child type |
struct |
A tuple of typed values |
map |
A collection of key-value pairs |