# 8.1. Data Types

Presto has a set of built-in data types, described below. Additional types can be provided by plugins.

Note

Connectors are not required to support all types. See connector documentation for details on supported types.

## Boolean

`BOOLEAN`

This type captures boolean values`true`

and`false`

.

## Integer

`TINYINT`

A 8-bit signed two’s complement integer with a minimum value of`-2^7`

and a maximum value of`2^7 - 1`

.

`SMALLINT`

A 16-bit signed two’s complement integer with a minimum value of`-2^15`

and a maximum value of`2^15 - 1`

.

`INTEGER`

A 32-bit signed two’s complement integer with a minimum value of`-2^31`

and a maximum value of`2^31 - 1`

. The name`INT`

is also available for this type.

`BIGINT`

A 64-bit signed two’s complement integer with a minimum value of`-2^63`

and a maximum value of`2^63 - 1`

.

## Floating-Point

`REAL`

A real is a 32-bit inexact, variable-precision implementing the IEEE Standard 754 for Binary Floating-Point Arithmetic.

`DOUBLE`

A double is a 64-bit inexact, variable-precision implementing the IEEE Standard 754 for Binary Floating-Point Arithmetic.

## Fixed-Precision

`DECIMAL`

A fixed precision decimal number. Precision up to 38 digits is supported but performance is best up to 18 digits.

The decimal type takes two literal parameters:

precision- total number of digitsscale- number of digits in fractional part. Scale is optional and defaults to 0.Example type definitions:

`DECIMAL(10,3)`

,`DECIMAL(20)`

Example literals:

`DECIMAL '10.3'`

,`DECIMAL '1234567890'`

,`1.1`

Note

For compatibility reasons decimal literals without explicit type specifier (e.g.

`1.2`

) are treated as the values of the`DOUBLE`

type by default, but this is subject to change in future releases. This behavior is controlled by:

- System wide property:
`parse-decimal-literals-as-double`

- Session wide property:
`parse_decimal_literals_as_double`

## String

`VARCHAR`

Variable length character data with an optional maximum length.

Example type definitions:

`varchar`

,`varchar(20)`

`CHAR`

Fixed length character data. A

`CHAR`

type without length specified has a default length of 1. A`CHAR(x)`

value always has`x`

characters. For instance, casting`dog`

to`CHAR(7)`

adds 4 implicit trailing spaces. Leading and trailing spaces are included in comparisons of`CHAR`

values. As a result, two character values with different lengths (`CHAR(x)`

and`CHAR(y)`

where`x != y`

) will never be equal.Example type definitions:

`char`

,`char(20)`

`VARBINARY`

Variable length binary data.

Note

Binary strings with length are not yet supported:

`varbinary(n)`

`JSON`

JSON value type, which can be a JSON object, a JSON array, a JSON number, a JSON string,`true`

,`false`

or`null`

.

## Date and Time

See also Legacy and New Timestamp

`DATE`

Calendar date (year, month, day).

Example:

`DATE '2001-08-22'`

`TIME`

Time of day (hour, minute, second, millisecond) without a time zone. Values of this type are parsed and rendered in the session time zone.

Example:

`TIME '01:02:03.456'`

`TIME WITH TIME ZONE`

Time of day (hour, minute, second, millisecond) with a time zone. Values of this type are rendered using the time zone from the value.

Example:

`TIME '01:02:03.456 America/Los_Angeles'`

`TIMESTAMP`

Instant in time that includes the date and time of day without a time zone. Values of this type are parsed and rendered in the session time zone.

Example:

`TIMESTAMP '2001-08-22 03:04:05.321'`

`TIMESTAMP WITH TIME ZONE`

Instant in time that includes the date and time of day with a time zone. Values of this type are rendered using the time zone from the value.

Example:

`TIMESTAMP '2001-08-22 03:04:05.321 America/Los_Angeles'`

`INTERVAL YEAR TO MONTH`

Span of years and months.

Example:

`INTERVAL '3' MONTH`

`INTERVAL DAY TO SECOND`

Span of days, hours, minutes, seconds and milliseconds.

Example:

`INTERVAL '2' DAY`

## Structural

`ARRAY`

An array of the given component type.

Example:

`ARRAY[1, 2, 3]`

`MAP`

A map between the given component types.

Example:

`MAP(ARRAY['foo', 'bar'], ARRAY[1, 2])`

`ROW`

A structure made up of named fields. The fields may be of any SQL type, and are accessed with field reference operator

`.`

Example:

`CAST(ROW(1, 2.0) AS ROW(x BIGINT, y DOUBLE))`

## Network Address

`IPADDRESS`

An IP address that can represent either an IPv4 or IPv6 address. Internally, the type is a pure IPv6 address. Support for IPv4 is handled using the

IPv4-mapped IPv6 addressrange (RFC 4291#section-2.5.5.2). When creating an`IPADDRESS`

, IPv4 addresses will be mapped into that range. When formatting an`IPADDRESS`

, any address within the mapped range will be formatted as an IPv4 address. Other addresses will be formatted as IPv6 using the canonical format defined inRFC 5952.Examples:

`IPADDRESS '10.0.0.1'`

,`IPADDRESS '2001:db8::1'`

## HyperLogLog

Calculating the approximate distinct count can be done much more cheaply than an exact count using the HyperLogLog data sketch. See HyperLogLog Functions.

`HyperLogLog`

A HyperLogLog sketch allows efficient computation of`approx_distinct()`

. It starts as a sparse representation, switching to a dense representation when it becomes more efficient.

`P4HyperLogLog`

A P4HyperLogLog sketch is similar to HyperLogLog, but it starts (and remains) in the dense representation.

## Quantile Digest

`QDigest`

A quantile digest (qdigest) is a summary structure which captures the approximate distribution of data for a given input set, and can be queried to retrieve approximate quantile values from the distribution. The level of accuracy for a qdigest is tunable, allowing for more precise results at the expense of space.

A qdigest can be used to give approximate answer to queries asking for what value belongs at a certain quantile. A useful property of qdigests is that they are additive, meaning they can be merged together without losing precision.

A qdigest may be helpful whenever the partial results of

`approx_percentile`

can be reused. For example, one may be interested in a daily reading of the 99th percentile values that are read over the course of a week. Instead of calculating the past week of data with`approx_percentile`

,`qdigest`

s could be stored daily, and quickly merged to retrieve the 99th percentile value.