Data types

Data can be stored in different formats. CrateDB has different types that can be specified if a table is created using the CREATE TABLE statement.

Data types play a central role as they limit what kind of data can be inserted, how it is stored and they also influence the behaviour when the records are queried.

Data type names are reserved words and need to be escaped when used as column names.

Table of contents

Overview

Supported types

CrateDB supports the following data types. Scroll down for more details.

Type

Description

Example

BOOLEAN

A boolean value

true or false

VARCHAR(n) and TEXT

A string of Unicode characters

'foobar'

SMALLINT, INTEGER and BIGINT

A signed integer value

12345 or -12345

REAL

An inexact single-precision floating-point value.

3.4028235e+38

DOUBLE PRECISION

An inexact double-precision floating-point value.

1.7976931348623157e+308

NUMERIC(precision, scale)

An exact fixed-point fractional number with an arbitrary, user-specified precision.

123.45

TIMESTAMP WITH TIME ZONE

Time and date with time zone

'1970-01-02T00:00:00+01:00'

TIMESTAMP WITHOUT TIME ZONE

Time and date without time zone

'1970-01-02T00:00:00'

DATE

A specific year, month and a day in UTC.

'2021-03-09'

TIME

A specific time as the number of milliseconds since midnight along with an optional time zone offset

'13:00:00' or '13:00:00+01:00'

BIT(n)

A bit sequence

B'00010010'

IP

An IP address (IPv4 or IPv6)

'127.0.0.1' or '0:0:0:0:0:ffff:c0a8:64'

OBJECT

Express an object

{
    "foo" = 'bar',
    "baz" = 'qux'
}

ARRAY

Express an array

[
    {"name" = 'Alice', "age" = 33},
    {"name" = 'Bob', "age" = 45}
]

GEO_POINT

A geographic data type comprised of a pair of coordinates (latitude and longitude)

[13.46738, 52.50463] or POINT( 13.46738 52.50463 )

GEO_SHAPE

Express arbitrary GeoJSON geometry objects

[13.46738, 52.50463] or POINT( 13.46738 52.50463 )

{
    type = 'Polygon',
    coordinates = [
        [
            [100.0, 0.0],
            [101.0, 0.0],
            [101.0, 1.0],
            [100.0, 1.0],
            [100.0, 0.0]
        ]
    ]
}

or:

'POLYGON ((5 5, 10 5, 10 10, 5 10, 5 5))'

Ranges and widths

This section lists all data types supported by CrateDB at a glance in tabular form, including some facts about their byte widths, value ranges and properties.

Please note that the byte widths do not equal the total storage sizes, which are likely to be larger due to additional metadata.

Type

Width

Range

Description

BOOLEAN

1 byte

true or false

Boolean type

VARCHAR(n)

variable

Minimum length: 1. Maximum length: 2^31-1 (upper integer range). 1

Strings of variable length. All Unicode characters are allowed.

TEXT

variable

Minimum length: 1. Maximum length: 2^31-1 (upper integer range). 1

Strings of variable length. All Unicode characters are allowed.

SMALLINT

2 bytes

-32,768 to 32,767

Small-range integer

INTEGER

4 bytes

-2^31 to 2^31-1

Typical choice for integer

BIGINT

8 bytes

-2^63 to 2^63-1

Large-range integer

NUMERIC

variable

Up to 131072 digits before, and up to 16383 digits after the decimal point

user-specified precision, exact

REAL

4 bytes

6 decimal digits precision

Inexact, variable-precision

DOUBLE PRECISION

8 bytes

15 decimal digits precision

Inexact, variable-precision

TIMESTAMP WITH TIME ZONE

8 bytes

292275054BC to 292278993AD

Time and date with time zone

TIMESTAMP WITHOUT TIME ZONE

8 bytes

292275054BC to 292278993AD

Time and date without time zone

DATE

8 bytes

292275054BC to 292278993AD

Date in UTC. Internally stored as BIGINT.

TIME WITH TIME ZONE

12 bytes

292275054BC to 292278993AD

00:00:00.000000 to 23:59:59.999999 zone: -18:00 to 18:00

BIT(n)

variable

A sequence of 0 or 1 digits. Minimum length: 1. Maximum length: 2^31-1 (upper integer range).

A string representation of a bit sequence.

IP

8 bytes

IP addresses are stored as BIGINT values.

A string representation of an IP address (IPv4 or IPv6).

OBJECT

variable

The theoretical maximum length (number of key/value pairs) is slightly below Java’s Integer.MAX_VALUE.

An object is structured as a collection of key-values, containing any other type, including further child objects.

ARRAY

variable

The theoretical maximum length is slightly below Java’s Integer.MAX_VALUE.

An array is structured as a sequence of any other type.

GEO_POINT

16 bytes

Each coordinate is stored as a DOUBLE PRECISION type.

A GEO_POINT is a geographic data type used to store latitude and longitude coordinates.

GEO_SHAPE

variable

Each coordinate is stored as a DOUBLE PRECISION type.

A GEO_SHAPE column can store different kinds of GeoJSON geometry objects.

Footnotes

1(1,2)

Using the Column Store limits the values of text columns to a maximum length of 32766 bytes. You can relax that limitation by either defining a column to not use the column store or by turning off indexing.

Primitive types

Primitive types are types with scalar values:

Null values

NULL

A NULL represents a missing value.

Note

NULL values are not the same as 0, an empty string (''), an empty object ({}), an empty array ([]), or any other kind of empty or zeroed data type.

You can use NULL values when inserting records to indicate the absence of a data point (i.e., the value for a specific column is not known).

Similarly, CrateDB will produce NULL values when, for example, data is missing from a outer left-join operation (i.e., when a row from one relation has no corresponding row in the joined relation).

If you insert a record without specifying the value for a particular column, CrateDB will insert a NULL value for that column.

For example:

cr> CREATE TABLE users (
...     first_name TEXT,
...     surname TEXT
... );
CREATE OK, 1 row affected (... sec)

Insert a record without specifying surname:

cr> INSERT INTO users (
...     first_name
... ) VALUES (
...     'Alice'
... );
INSERT OK, 1 row affected (... sec)

The resulting row will have a NULL value for surname:

cr> SELECT
...     first_name,
...     surname
... FROM users
... WHERE first_name = 'Alice';
+------------+---------+
| first_name | surname |
+------------+---------+
| Alice      | NULL    |
+------------+---------+
SELECT 1 row in set (... sec)

You can prevent NULL values being inserted altogether with a NOT NULL constraint, like so:

cr> CREATE TABLE users_with_surnames (
...     first_name TEXT,
...     surname TEXT NOT NULL
... );
CREATE OK, 1 row affected (... sec)

Now, when you try to insert a user without a surname, it will produce an error:

cr> INSERT INTO users_with_surnames (
...     first_name
... ) VALUES (
...     'Alice'
... );
SQLParseException["surname" must not be null]

Boolean values

BOOLEAN

A basic boolean type accepting true and false as values.

Example:

cr> CREATE TABLE my_table (
...     first_column BOOLEAN
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     first_column
... ) VALUES (
...     true
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT * FROM my_table;
+--------------+
| first_column |
+--------------+
| TRUE         |
+--------------+
SELECT 1 row in set (... sec)

Character data

Character types are general purpose strings of character data.

CrateDB supports the following character types:

Note

Only character data types without specified length can be analyzed for full text search.

By default, the plain analyzer is used.

VARCHAR(n)

The VARCHAR(n) (or CHARACTER VARYING(n)) type represents variable length strings. All Unicode characters are allowed.

The optional length specification n is a positive integer that defines the maximum length, in characters, of the values that have to be stored or cast. The minimum length is 1. The maximum length is defined by the upper integer range.

An attempt to store a string literal that exceeds the specified length of the character data type results in an error.

cr> CREATE TABLE users (
...     id VARCHAR,
...     name VARCHAR(3)
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO users (
...     id,
...     name
... ) VALUES (
...     '1',
...     'Alice Smith'
... );
SQLParseException['Alice Smith' is too long for the text type of length: 3]

If the excess characters are all spaces, the string literal will be truncated to the specified length.

cr> INSERT INTO users (
...     id,
...     name
... ) VALUES (
...     '1',
...     'Bob     '
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT
...    id,
...    name,
...    char_length(name) AS name_length
... FROM users;
+----+------+-------------+
| id | name | name_length |
+----+------+-------------+
| 1  | Bob  |           3 |
+----+------+-------------+
SELECT 1 row in set (... sec)

If a value is explicitly cast to VARCHAR(n), then an over-length value will be truncated to n characters without raising an error.

cr> SELECT 'Alice Smith'::VARCHAR(5) AS name;
+-------+
| name  |
+-------+
| Alice |
+-------+
SELECT 1 row in set (... sec)

CHARACTER VARYING and VARCHAR without the length specifier are aliases for the text data type, see also type aliases.

TEXT

A text-based basic type containing one or more characters. All Unicode characters are allowed.

Create table

cr> CREATE TABLE users ( … name TEXT … ); CREATE OK, 1 row affected (… sec)

Insert data:

cr> INSERT INTO users (
...     name
... ) VALUES (
...     '🌻 Alice 🌻'
... );
INSERT OK, 1 row affected (... sec)

Query data:

cr> SELECT * FROM users;
+-------------+
| name        |
+-------------+
| 🌻 Alice 🌻 |
+-------------+
SELECT 1 row in set (... sec)

Note

The maximum indexed string length is restricted to 32766 bytes when encoded with UTF-8 unless the string is analyzed using full text or indexing and the usage of the Column store is disabled.

There is no difference in storage costs among all character data types.

json

A type representing a JSON string.

This type only exists for compatibility and interoperability with PostgreSQL. It cannot to be used in data definition statements and it is not possible to use it to store data. To store JSON data use the existing OBJECT type. It is a more powerful alternative that offers more flexibility and delivering the same benefits.

The JSON types primary use is in type casting for interoperability with PostgreSQL clients which may use the JSON type. The following type casts are example of supported usage of the JSON data type:

Casting from STRING to JSON:

cr> SELECT '{"x": 10}'::json;
+-------------+
| '{"x": 10}' |
+-------------+
| {"x": 10}   |
+-------------+
SELECT 1 row in set (... sec)

Casting from JSON to OBJECT:

cr> SELECT ('{"x": 10}'::json)::object;
+-----------+
| {"x"=10}  |
+-----------+
| {"x": 10} |
+-----------+
SELECT 1 row in set (... sec)

Casting from OBJECT to JSON:

cr> SELECT {x=10}::json;
+------------+
| '{"x":10}' |
+------------+
| {"x":10}   |
+------------+
SELECT 1 row in set (... sec)

Numeric data

CrateDB supports the following numeric types:

Note

The REAL and DOUBLE PRECISION data types are inexact, variable-precision floating-point types, meaning that these types are stored as an approximation.

Accordingly, storage, calculation, and retrieval of the value will not always result in an exact representation of the actual floating-point value. For instance, the result of applying SUM or AVG aggregate functions may slightly vary between query executions or comparing floating-point values for equality might not always match.

CrateDB conforms to the IEEE 754 standard concerning special values for floating-point data types, meaning that NaN, Infinity, -Infinity (negative infinity), and -0 (signed zero) are all supported:

cr> SELECT
...     0.0 / 0.0 AS a,
...     1.0 / 0.0 AS B,
...     1.0 / -0.0 AS c;
+-----+----------+-----------+
| a   | b        | c         |
+-----+----------+-----------+
| NaN | Infinity | -Infinity |
+-----+----------+-----------+
SELECT 1 row in set (... sec)

These special numeric values can also be inserted into a column of type REAL or DOUBLE PRECISION using a TEXT literal.

For instance:

cr> CREATE TABLE my_table (
...     column_1 INTEGER,
...     column_2 BIGINT,
...     column_3 SMALLINT,
...     column_4 DOUBLE PRECISION,
...     column_5 REAL,
...     column_6 CHAR
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     column_4,
...     column_5
... ) VALUES (
...     'NaN',
...     'Infinity'
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT
...     column_4,
...     column_5
... FROM my_table;
+----------+----------+
| column_4 | column_5 |
+----------+----------+
| NaN      | Infinity |
+----------+----------+
SELECT 1 row in set (... sec)

SMALLINT

A small integer.

Limited to two bytes, with a range from -32,768 to 32,767.

Example:

cr> CREATE TABLE my_table (
...     number SMALLINT
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     32767
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT number FROM my_table;
+--------+
| number |
+--------+
| 32767  |
+--------+
SELECT 1 row in set (... sec)

INTEGER

An integer.

Limited to four bytes, with a range from -2^31 to 2^31-1.

Example:

cr> CREATE TABLE my_table (
...     number INTEGER
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     2147483647
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT number FROM my_table;
+------------+
| number     |
+------------+
| 2147483647 |
+------------+
SELECT 1 row in set (... sec)

BIGINT

A large integer.

Limited to eight bytes, with a range from -2^63 to 2^63-1.

Example:

cr> CREATE TABLE my_table (
...     number BIGINT
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     9223372036854775807
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT number FROM my_table;
+---------------------+
| number              |
+---------------------+
| 9223372036854775807 |
+---------------------+
SELECT 1 row in set (... sec)

NUMERIC(precision, scale)

An exact fixed-point fractional number with an arbitrary, user-specified precision.

Variable size, with up to 131072 digits before the decimal point and up to 16383 digits after the decimal point.

For example, using a cast from a string literal:

cr> SELECT NUMERIC(5, 2) '123.45' AS number;
+--------+
| number |
+--------+
| 123.45 |
+--------+
SELECT 1 row in set (... sec)

Note

The NUMERIC type is only supported as a type literal (i.e., for use in SQL expressions, like a type cast, as above).

You cannot create table columns of type NUMERIC.

This type is usually used when it is important to preserve exact precision or handle values that exceed the range of the numeric types of the fixed length. The aggregations and arithmetic operations on numeric values are much slower compared to operations on the integer or floating-point types.

The NUMERIC type can be configured with the precision and scale. The precision value of a numeric is the total count of significant digits in the unscaled numeric value. The scale value of a numeric is the count of decimal digits in the fractional part, to the right of the decimal point. For example, the number 123.45 has a precision of 5 and a scale of 2. Integers have a scale of zero.

To declare the NUMERIC type with the precision and scale, use the syntax:

NUMERIC(precision, scale)

Alternatively, only the precision can be specified, the scale will be zero or positive integer in this case:

NUMERIC(precision)

Without configuring the precision and scale the NUMERIC type value will be represented by an unscaled value of the unlimited precision:

NUMERIC

The NUMERIC type is internally backed by the Java BigDecimal class. For more detailed information about its behaviour, see BigDecimal documentation.

REAL

An inexact single-precision floating-point value.

Limited to four bytes, six decimal digits precision.

Example:

cr> CREATE TABLE my_table (
...     number REAL
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     3.4028235e+38
... );
INSERT OK, 1 row affected (... sec)

Tip

3.4028235+38 represents the value 3.4028235 × 1038

cr> SELECT number FROM my_table;
+---------------+
| number        |
+---------------+
| 3.4028235e+38 |
+---------------+
SELECT 1 row in set (... sec)

You can insert values which exceed the maximum precision, like so:

cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     3.4028234664e+38
... );
INSERT OK, 1 row affected (... sec)

However, the recorded value will be an approximation of the original (i.e., the additional precision is lost):

cr> SELECT number FROM my_table;
+---------------+
| number        |
+---------------+
| 3.4028235e+38 |
+---------------+
SELECT 1 row in set (... sec)

DOUBLE PRECISION

An inexact number with variable precision supporting double-precision floating-point values.

Limited to eight bytes, with 15 decimal digits precision.

Example:

cr> CREATE TABLE my_table (
...     number DOUBLE PRECISION
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     1.7976931348623157e+308
... );
INSERT OK, 1 row affected (... sec)

Tip

1.7976931348623157e+308 represents the value 1.7976931348623157 × 10308

cr> SELECT number FROM my_table;
+-------------------------+
| number                  |
+-------------------------+
| 1.7976931348623157e+308 |
+-------------------------+
SELECT 1 row in set (... sec)

You can insert values which exceed the maximum precision, like so:

cr> INSERT INTO my_table (
...     number
... ) VALUES (
...     1.79769313486231572014e+308
... );
INSERT OK, 1 row affected (... sec)

However, the recorded value will be an approximation of the original (i.e., the additional precision is lost):

cr> SELECT number FROM my_table;
+-------------------------+
| number                  |
+-------------------------+
| 1.7976931348623157e+308 |
+-------------------------+
SELECT 1 row in set (... sec)

Dates and times

CrateDB supports the following types for dates and times:

With a few exceptions (noted below) the + and - operators can be used to create arithmetic expressions with temporal operands:

Operand

Operator

Operand

TIMESTAMP

-

TIMESTAMP

INTERVAL

+

TIMESTAMP

TIMESTAMP

+ or -

INTERVAL

INTERVAL

+ or -

INTERVAL

Note

If an object column is dynamically created, the type detection will not recognize date and time types, meaning that date and time type columns must always be declared beforehand.

TIMESTAMP

A timestamp expresses a specific date and time as the number of milliseconds since the Unix epoch (i.e., 1970-01-01T00:00:00Z).

Timestamps can be expressed as string literals (e.g., '1970-01-02T00:00:00') with the following syntax:

date-element [time-separator [time-element [offset]]]

date-element:   yyyy-MM-dd
time-separator: 'T' | ' '
time-element:   HH:mm:ss [fraction]
fraction:       '.' digit+
offset:         {+ | -} HH [:mm] | 'Z'

See also

For more information about date and time formatting, see Java 15: Patterns for Formatting and Parsing.

Time zone syntax as defined by ISO 8601 time zone designators.

Internally, CrateDB stores timestamps as BIGINT values, which are limited to eight bytes.

If you cast a BIGINT to a TIMEZONE, the integer value will be interpreted as the number of milliseconds since the Unix epoch.

Using the date_format() function, for readability:

cr> SELECT
...     date_format(0::TIMESTAMP) AS ts_0,
...     date_format(1000::TIMESTAMP) AS ts_1;
+-----------------------------+-----------------------------+
| ts_0                        | ts_1                        |
+-----------------------------+-----------------------------+
| 1970-01-01T00:00:00.000000Z | 1970-01-01T00:00:01.000000Z |
+-----------------------------+-----------------------------+
SELECT 1 row in set (... sec)

If you cast a REAL or a DOUBLE PRECISION to a TIMESTAMP, the numeric value wil be interpreted as the number of seconds since the Unix epoch, with fractional values approximated to the nearest millisecond:

cr> SELECT
...     date_format(0::TIMESTAMP) AS ts_0,
...     date_format(1.5::TIMESTAMP) AS ts_1;
+-----------------------------+-----------------------------+
| ts_0                        | ts_1                        |
+-----------------------------+-----------------------------+
| 1970-01-01T00:00:00.000000Z | 1970-01-01T00:00:01.500000Z |
+-----------------------------+-----------------------------+
SELECT 1 row in set (... sec)

If you cast a literal to a TIMESTAMP, years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol. See also Year.parse Javadoc:

cr> SELECT '+292278993-12-31T23:59:59.999Z'::TIMESTAMP as tmstp;
+---------------------+
|               tmstp |
+---------------------+
| 9223372017129599999 |
+---------------------+
SELECT 1 row in set (... sec)

Caution

Due to internal date parsing, the full BIGINT range is not supported for timestamp values. The valid range of dates is from 292275054BC to 292278993AD.

When inserting timestamps smaller than -999999999999999 (equal to -29719-04-05T22:13:20.001Z) or bigger than 999999999999999 (equal to 33658-09-27T01:46:39.999Z) rounding issues may occur.

A TIMESTAMP can be further defined as:

WITH TIME ZONE

If you define a timestamp as TIMESTAMP WITH TIME ZONE, CrateDB will convert string literals to Coordinated Universal Time (UTC) using the offset value (e.g., +01:00 for plus one hour or Z for UTC).

Example:

cr> CREATE TABLE my_table (
...     ts_tz_1 TIMESTAMP WITH TIME ZONE,
...     ts_tz_2 TIMESTAMP WITH TIME ZONE
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     ts_tz_1,
...     ts_tz_2
... ) VALUES (
...     '1970-01-02T00:00:00',
...     '1970-01-02T00:00:00+01:00'
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT
...     ts_tz_1,
...     ts_tz_2
... FROM my_table;
+----------+----------+
|  ts_tz_1 |  ts_tz_2 |
+----------+----------+
| 86400000 | 82800000 |
+----------+----------+
SELECT 1 row in set (... sec)

You can use date_format() to make the output easier to read:

cr> SELECT
...     date_format('%Y-%m-%dT%H:%i', ts_tz_1) AS ts_tz_1,
...     date_format('%Y-%m-%dT%H:%i', ts_tz_2) AS ts_tz_2
... FROM my_table;
+------------------+------------------+
| ts_tz_1          | ts_tz_2          |
+------------------+------------------+
| 1970-01-02T00:00 | 1970-01-01T23:00 |
+------------------+------------------+
SELECT 1 row in set (... sec)

Notice that ts_tz_2 is smaller than ts_tz_1 by one hour. CrateDB used the +01:00 offset (i.e., ahead of UTC by one hour) to convert the second timestamp into UTC prior to insertion. Contrast this with the behavior of WITHOUT TIME ZONE.

Note

TIMESTAMPTZ is an alias for TIMESTAMP WITH TIME ZONE.

Caution

In the absence of an explicit WITH TIME ZONE or WITHOUT TIME ZONE, CrateDB will interpret TIMEZONE as an alias for TIMESTAMP WITH TIME ZONE.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. CrateDB 4.0 deprecated this alias and behavior may change in a future version of CrateDB (see tracking issue #11491). To avoid issued, we recommend that you always specify WITH TIME ZONE or WITHOUT TIME ZONE.

WITHOUT TIME ZONE

If you define a timestamp as TIMESTAMP WITHOUT TIME ZONE, CrateDB will convert string literals to Coordinated Universal Time (UTC) without using the offset value (i.e., any time zone information present is stripped prior to insertion).

Example:

cr> CREATE TABLE my_table (
...     ts_1 TIMESTAMP WITHOUT TIME ZONE,
...     ts_2 TIMESTAMP WITHOUT TIME ZONE
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     ts_1,
...     ts_2
... ) VALUES (
...     '1970-01-02T00:00:00',
...     '1970-01-02T00:00:00+01:00'
... );
INSERT OK, 1 row affected (... sec)

Using the date_format() function, for readability:

cr> SELECT
...     date_format('%Y-%m-%dT%H:%i', ts_1) AS ts_1,
...     date_format('%Y-%m-%dT%H:%i', ts_2) AS ts_2
... FROM my_table;
+------------------+------------------+
| ts_1             | ts_2             |
+------------------+------------------+
| 1970-01-02T00:00 | 1970-01-02T00:00 |
+------------------+------------------+
SELECT 1 row in set (... sec)

Notice that ts_1 and ts_2 are identical. CrateDB ignored the +01:00 offset (i.e., ahead of UTC by one hour) when processing the second string literal. Contrast this with the behavior of WITH TIME ZONE.

Caution

In the absence of an explicit WITH TIME ZONE or WITHOUT TIME ZONE, CrateDB will interpret TIMEZONE as an alias for TIMESTAMP WITH TIME ZONE.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. CrateDB 4.0 deprecated this alias and behavior may change in a future version of CrateDB (see tracking issue #11491). To avoid issued, we recommend that you always specify WITH TIME ZONE or WITHOUT TIME ZONE.

AT TIME ZONE

You can use the AT TIME ZONE clause to modify a timestamp in two different ways. It converts a timestamp without time zone to a timestamp with time zone and vice versa.

Note

The AT TIME ZONE type is only supported as a type literal (i.e., for use in SQL expressions, like a type cast, as below).

You cannot create table columns of type AT TIME ZONE.

Convert a timestamp time zone

If you use AT TIME ZONE tz with a TIMESTAMP WITH TIME ZONE, CrateDB will convert timestamp to time zone tz and cast the return value as a TIMESTAMP WITHOUT TIME ZONE (which discards the time zone information). This process effectively allows you to correct the offset used to calculate UTC.

Example:

cr> CREATE TABLE my_table (
...     ts_tz TIMESTAMP WITH TIME ZONE
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     ts_tz
... ) VALUES (
...     '1970-01-02T00:00:00'
... );
INSERT OK, 1 row affected (... sec)

Using the date_format() function, for readability:

cr> SELECT date_format(
...     '%Y-%m-%dT%H:%i', ts_tz AT TIME ZONE '+01:00'
... ) AS ts
... FROM my_table;
+------------------+
| ts               |
+------------------+
| 1970-01-02T01:00 |
+------------------+
SELECT 1 row in set (... sec)

Tip

The AT TIME ZONE clause does the same as the timezone() function:

cr> SELECT
...     date_format('%Y-%m-%dT%H:%i', ts_tz AT TIME ZONE '+01:00') AS ts_1,
...     date_format('%Y-%m-%dT%H:%i', timezone('+01:00', ts_tz)) AS ts_2
... FROM my_table;
+------------------+------------------+
| ts_1             | ts_2             |
+------------------+------------------+
| 1970-01-02T01:00 | 1970-01-02T01:00 |
+------------------+------------------+
SELECT 1 row in set (... sec)
Add a timestamp time zone

If you use AT TIME ZONE with a TIMESTAMP WITHOUT TIME ZONE, CrateDB will add the missing time zone information, recalculate the timestamp in UTC, and cast the return value as a TIMESTAMP WITH TIME ZONE.

Example:

cr> CREATE TABLE my_table (
...     ts TIMESTAMP WITHOUT TIME ZONE
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     ts
... ) VALUES (
...     '1970-01-02T00:00:00'
... );
INSERT OK, 1 row affected (... sec)

Using the date_format() function, for readability:

cr> SELECT date_format(
...     '%Y-%m-%dT%H:%i', ts AT TIME ZONE '+01:00'
... ) AS ts_tz
... FROM my_table;
+------------------+
| ts_tz            |
+------------------+
| 1970-01-01T23:00 |
+------------------+
SELECT 1 row in set (... sec)

Tip

The AT TIME ZONE clause does the same as the timezone() function:

cr> SELECT date_format(
...     '%Y-%m-%dT%H:%i', timezone('+01:00', ts)
... ) AS ts_tz
... FROM my_table;
+------------------+
| ts_tz            |
+------------------+
| 1970-01-01T23:00 |
+------------------+
SELECT 1 row in set (... sec)

TIME

A TIME expresses a specific time as the number of milliseconds since midnight along with a time zone offset.

Limited to 12 bytes, with a time range from 00:00:00.000000 to 23:59:59.999999 and a time zone range from -18:00 to 18:00.

Caution

CrateDB does not support TIME by itself or TIME WITHOUT TIME ZONE. You must always specify TIME WITH TIME ZONE or its alias TIMETZ.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. This behavior may change in a future version of CrateDB (see tracking issue #11491).

Note

The TIME type is only supported as a type literal (i.e., for use in SQL expressions, like a type cast, as below).

You cannot create table columns of type TIME.

Times can be expressed as string literals (e.g., '13:00:00') with the following syntax:

time-element [offset]

time-element: time-only [fraction]
time-only:    HH[[:][mm[:]ss]]
fraction:     '.' digit+
offset:       {+ | -} time-only | geo-region
geo-region:   As defined by ISO 8601.

Above, fraction accepts up to six digits, with a precision in microseconds.

See also

For more information about time formatting, see Java 15: Patterns for Formatting and Parsing.

Time zone syntax as defined by ISO 8601 time zone designators.

For example:

cr> SELECT '13:00:00'::TIMETZ AS t_tz;
+------------------+
| t_tz             |
+------------------+
| [46800000000, 0] |
+------------------+
SELECT 1 row in set (... sec)

The value of first element is the number of milliseconds since midnight. The value of the second element is the number of seconds corresponding to the time zone offset (zero in this instance, as no time zone was specified).

For example, with a +01:00 time zone:

cr> SELECT '13:00:00+01:00'::TIMETZ AS t_tz;
+---------------------+
| t_tz                |
+---------------------+
| [46800000000, 3600] |
+---------------------+
SELECT 1 row in set (... sec)

The time zone offset is calculated as 3600 seconds, which is equivalent to an hour.

Negative time zone offsets will return negative seconds:

cr> SELECT '13:00:00-01:00'::TIMETZ AS t_tz;
+----------------------+
| t_tz                 |
+----------------------+
| [46800000000, -3600] |
+----------------------+
SELECT 1 row in set (... sec)

Here’s an example that uses fractional seconds:

cr> SELECT '13:59:59.999999'::TIMETZ as t_tz;
+------------------+
| t_tz             |
+------------------+
| [50399999999, 0] |
+------------------+
SELECT 1 row in set (... sec)

Caution

The current implementation of the TIME type has the following limitations:

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. This behavior may change in a future version of CrateDB (see tracking issue #11528).

DATE

A DATE expresses a specific year, month and a day in UTC.

Internally, CrateDB stores dates as BIGINT values, which are limited to eight bytes.

If you cast a BIGINT to a DATE, the integer value will be interpreted as the number of milliseconds since the Unix epoch. If you cast a REAL or a DOUBLE PRECISION to a DATE, the numeric value wil be interpreted as the number of seconds since the Unix epoch.

If you cast a literal to a DATE, years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol. See also Year.parse Javadoc:

cr> SELECT '+10000-03-09'::DATE as date;
+-----------------+
|            date |
+-----------------+
| 253408176000000 |
+-----------------+
SELECT 1 row in set (... sec)

Caution

Due to internal date parsing, the full BIGINT range is not supported for timestamp values. The valid range of dates is from 292275054BC to 292278993AD.

When inserting dates smaller than -999999999999999 (equal to -29719-04-05) or bigger than 999999999999999 (equal to 33658-09-27) rounding issues may occur.

Warning

The DATE type was not designed to allow time-of-day information (i.e., it is supposed to have a resolution of one day).

However, CrateDB allows you violate that constraint by casting any number of milliseconds within limits to a DATE type. The result is then returned as a TIMESTAMP. When used in conjunction with arithmetic expressions, these TIMESTAMP values may produce unexpected results.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. This behavior may change in a future version of CrateDB (see tracking issue #11528).

Caution

The current implementation of the DATE type has the following limitations:

  • DATE types cannot be added or subtracted to or from other DATE types as expected (i.e., to calculate the difference between the two in a number of days).

    Doing so will convert both DATE values into TIMESTAMP values before performing the operation, resulting in a TIMESTAMP value corresponding to a full date and time (see WARNING above).

  • Numeric data types cannot be added to or subtracted from DATE types as expected (e.g., to increase the date by n days).

    Doing so will, for example, convert the DATE into a TIMESTAMP and increase the value by n milliseconds (see WARNING above).

  • TIME types cannot be added to or subtracted from DATE types.

  • INTERVAL types cannot be added to or subtracted from DATE types.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. This behavior may change in a future version of CrateDB (see tracking issue #11528).

Note

The DATE type is only supported as a type literal (i.e., for use in SQL expressions, like a type cast, as below).

You cannot create table columns of type DATE.

Dates can be expressed as string literals (e.g., '2021-03-09') with the following syntax:

yyyy-MM-dd

See also

For more information about date and time formatting, see Java 15: Patterns for Formatting and Parsing.

For example, using the date_format() function, for readability:

cr> SELECT
...    date_format(
...        '%Y-%m-%d',
...        '2021-03-09'::DATE
...    ) AS date;
+------------+
| date       |
+------------+
| 2021-03-09 |
+------------+
SELECT 1 row in set (... sec)

INTERVAL

An INTERVAL represents a span of time.

Note

The INTERVAL type is only supported as a type literal (i.e., for use in SQL expressions, like a type cast, as above).

You cannot create table columns of type INTERVAL.

The basic syntax is:

INTERVAL <quantity> <unit>

Where unit can be any of the following:

  • YEAR

  • MONTH

  • DAY

  • HOUR

  • MINUTE

  • SECOND

For example:

cr> SELECT INTERVAL '1' DAY AS result;
+----------------+
| result         |
+----------------+
| 1 day 00:00:00 |
+----------------+
SELECT 1 row in set (... sec)

Intervals can be positive or negative:

cr> SELECT INTERVAL -'1' DAY AS result;
+------------------+
| result           |
+------------------+
| -1 days 00:00:00 |
+------------------+
SELECT 1 row in set (... sec)

When using SECOND, you can define fractions of a seconds (with a precision of zero to six digits):

cr> SELECT INTERVAL '1.5' SECOND AS result;
+--------------+
| result       |
+--------------+
| 00:00:01.500 |
+--------------+
SELECT 1 row in set (... sec)

Caution

The INTERVAL data type does not currently support the input units MILLENNIUM, CENTURY, DECADE, MILLISECOND, or MICROSECOND.

This behaviour does not comply with standard SQL and is incompatible with PostgreSQL. This behavior may change in a future version of CrateDB (see tracking issue #11490).

You can also use the following syntax to express an interval:

INTERVAL <string>

Where string describes the interval using one of the recognized formats:

Description

Example

Equivalent

Standard SQL format (year-month)

1-2

1 year 2 months

Standard SQL format

1-2 3 4:05:06

1 year 2 months 3 days 4 hours 5 minutes 6 seconds

Standard SQL format (day-time)

3 4:05:06

3 days 4 hours 5 minutes 6 seconds

PostgreSQL interval format

1 year 2 months 3 days 4 hours 5 minutes 6 seconds

1 year 2 months 3 days 4 hours 5 minutes 6 seconds

ISO 8601 duration format

P1Y2M3DT4H5M6S

1 year 2 months 3 days 4 hours 5 minutes 6 seconds

For example:

cr> SELECT INTERVAL '1-2 3 4:05:06' AS result;
+-------------------------------+
| result                        |
+-------------------------------+
| 1 year 2 mons 3 days 04:05:06 |
+-------------------------------+
SELECT 1 row in set (... sec)

You can limit the precision of an interval by specifying <unit> TO <unit> after the interval string.

For example, you can use YEAR TO MONTH to limit an interval to a day-month value:

cr> SELECT INTERVAL '1-2 3 4:05:06' YEAR TO MONTH AS result;
+------------------------+
| result                 |
+------------------------+
| 1 year 2 mons 00:00:00 |
+------------------------+
SELECT 1 row in set (... sec)

You can use DAY TO HOUR, as another example, to limit a day-time interval to days and hours:

cr> SELECT INTERVAL '3 4:05:06' DAY TO HOUR AS result;
+-----------------+
| result          |
+-----------------+
| 3 days 04:00:00 |
+-----------------+
SELECT 1 row in set (... sec)

Tip

You can use intervals in combination with CURRENT_TIMESTAMP to calculate values that are offset relative to the current date and time.

For example, to calculate a timestamp corresponding to exactly one day ago, use:

cr> SELECT CURRENT_TIMESTAMP - INTERVAL '1' DAY AS result;
+---------------+
| result        |
+---------------+
| ...           |
+---------------+
SELECT 1 row in set (... sec)

Bit strings

BIT(n)

A string representation of a bit sequence, useful for visualizing a bit mask.

Values of this type can be created using the bit string literal syntax. A bit string starts with the B prefix, followed by a sequence of 0 or 1 digits quoted within single quotes '.

An example:

B'00010010'

The optional length specification n is a positive integer that defines the maximum length, in characters, of the values that have to be stored or cast. The minimum length is 1. The maximum length is defined by the upper integer range.

For example:

cr> CREATE TABLE my_table (
...     bit_mask BIT(4)
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     bit_mask
... ) VALUES (
...     B'0110'
... );
INSERT OK, 1 row affected  (... sec)
cr> SELECT bit_mask FROM my_table;
+----------+
| bit_mask |
+----------+
| B'0110'  |
+----------+
SELECT 1 row in set (... sec)

Inserting values that are either too short or too long results in an error:

cr> INSERT INTO my_table (
...     bit_mask
... ) VALUES (
...    B'00101'
... );
SQLParseException[bit string length 5 does not match type bit(4)]

IP addresses

IP

An IP is a string representation of an IP address (IPv4 or IPv6).

Internally IP addresses are stored as BIGINT values, allowing expected sorting, filtering, and aggregation.

For example:

cr> CREATE TABLE my_table (
...     fqdn TEXT,
...     ip_addr IP
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     fqdn,
...     ip_addr
... ) VALUES (
...     'localhost',
...     '127.0.0.1'
... ), (
...     'router.local',
...     '0:0:0:0:0:ffff:c0a8:64'
... );
INSERT OK, 2 rows affected (... sec)
cr> SELECT fqdn, ip_addr FROM my_table ORDER BY fqdn;
+--------------+------------------------+
| fqdn         | ip_addr                |
+--------------+------------------------+
| localhost    | 127.0.0.1              |
| router.local | 0:0:0:0:0:ffff:c0a8:64 |
+--------------+------------------------+
SELECT 2 rows in set (... sec)

The fqdn column (see Fully Qualified Domain Name) will accept any value because it was specified as TEXT. However, trying to insert fake.ip won’t work, because it is not a correctly formatted IP address:

cr> INSERT INTO my_table (
...     fqdn,
...     ip_addr
... ) VALUES (
...     'localhost',
...     'fake.ip'
... );
SQLParseException[Cannot cast `'fake.ip'` of type `text` to type `ip`]

IP addresses support the << operator, which checks for subnet inclusion using CIDR notation. The left-hand operand must an IP type and the right-hand must be TEXT type (e.g., '192.168.1.5' << '192.168.1/24').

Container types

Container types are types with nonscalar values that may contain other values:

Objects

OBJECT

An object is structured as a collection of key-values.

An object can contain any other type, including further child objects. An OBJECT column can be schemaless or can have a defined (i.e., enforced) schema.

Objects are not the same as JSON objects, although they share a lot of similarities. However, objects can be inserted as JSON strings.

Syntax:

<columnName> OBJECT
    [ ({DYNAMIC|STRICT|IGNORED}) ]
    [ AS ( <columnDefinition>* ) ]

The only required syntax is OBJECT.

The column policy (DYNAMIC, STRICT, or IGNORED) is optional and defaults to DYNAMIC.

If the optional list of subcolumns (columnDefinition) is omitted, the object will have no schema. CrateDB will create a schema for DYNAMIC objects upon first insert.

Example:

cr> CREATE TABLE my_table (
...     title TEXT,
...     quotation OBJECT,
...     protagonist OBJECT(STRICT) AS (
...         age INTEGER,
...         first_name TEXT,
...         details OBJECT AS (
...             birthday TIMESTAMP WITH TIME ZONE
...         )
...     )
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     title,
...     quotation,
...     protagonist
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "words" = 'Curiouser and curiouser!',
...         "length" = 3
...     },
...     {
...         "age" = '10',
...         "first_name" = 'Alice',
...         "details" = {
...             "birthday" = '1852-05-04T00:00Z'::TIMESTAMPTZ
...         }
...     }
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT
...     protagonist['first_name'] AS name,
...     date_format(
...         '%D %b %Y',
...         'GMT',
...         protagonist['details']['birthday']
...      ) AS born,
...     protagonist['age'] AS age
... FROM my_table;
+-------+--------------+-----+
| name  | born         | age |
+-------+--------------+-----+
| Alice | 4th May 1852 |  10 |
+-------+--------------+-----+
SELECT 1 row in set (... sec)
Object column policy
STRICT

If the column policy is configured as STRICT, CrateDB will reject any subcolumn that is not defined upfront by columnDefinition.

Example:

cr> CREATE TABLE my_table (
...     title TEXT,
...     protagonist OBJECT(STRICT) AS (
...         name TEXT
...     )
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     title,
...     protagonist
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "age" = '10',
...     }
... );
SQLParseException[line 8:5: no viable alternative at input 'VALUES (\n    'Alice in Wonderland',\n    {\n        "age" = '10',\n    }']

The insert above failed because the protagonist column defines a name column and does not define an age column.

Note

Objects with a STRICT column policy and no columnDefinition will have one unusable column that will always be NULL.

DYNAMIC

If the column policy is configured as DYNAMIC (the default), inserts may dynamically add new subcolumns to the object definition.

Example:

cr> CREATE TABLE my_table (
...     title TEXT,
...     quotation OBJECT
... );
CREATE OK, 1 row affected (... sec)

The following statement is equivalent to the above:

cr> CREATE TABLE my_table (
...     title TEXT,
...     quotation OBJECT(DYNAMIC)
... );
CREATE OK, 1 row affected (... sec)

The following statement is also equivalent to the above:

cr> CREATE TABLE my_table (
...     title TEXT,
...     quotation OBJECT(DYNAMIC) AS (
...         words TEXT,
...         length SMALLINT
...     )
... );
CREATE OK, 1 row affected (... sec)

You can insert using the existing columns:

cr> INSERT INTO my_table (
...     title,
...     quotation
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "words" = 'Curiouser and curiouser!',
...         "length" = 3
...     }
... );
INSERT OK, 1 row affected (... sec)

Or you can add new columns:

cr> INSERT INTO my_table (
...     title,
...     quotation
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "words" = 'DRINK ME',
...         "length" = 2,
...         "chapter" = 1
...     }
... );
INSERT OK, 1 row affected (... sec)

All rows have the same columns (including newly added columns), but missing records will be returned as NULL values:

cr> SELECT
...     quotation['chapter'] as chapter,
...     quotation['words'] as quote
... FROM my_table
... ORDER BY chapter ASC;
+---------+--------------------------+
| chapter | quote                    |
+---------+--------------------------+
|       1 | DRINK ME                 |
|    NULL | Curiouser and curiouser! |
+---------+--------------------------+
SELECT 2 rows in set (... sec)

New columns are usable like any other subcolumn. You can retrieve them, sort by them, and use them in where clauses.

Note

Adding new columns to an object with a DYNAMIC policy will affect the schema of the table.

Once a column is added, it shows up in the information_schema.columns table and its type and attributes are fixed. If a new column a was added with type INTEGER, adding strings to the column will result in an error.

Dynamically added columns will always be analyzed as-is with the plain analyzer, which means the column will be indexed but not tokenized in the case of TEXT columns.

IGNORED

If the column policy is configured as IGNORED, inserts may dynamically add new subcolumns to the object definition. However, dynamically added subcolumns do not cause a schema update and the values contained will not be indexed.

Because dynamically created columns are not recorded in the schema, you can insert mixed types into them. For example, one row may insert an integer and the next row may insert an object. Objects with a STRICT or DYNAMIC column policy do not allow this.

Example:

cr> CREATE TABLE my_table (
...     title TEXT,
...     protagonist OBJECT(IGNORED) AS (
...         name TEXT,
...         chapter SMALLINT
...     )
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table (
...     title,
...     protagonist
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "name" = 'Alice',
...         "chapter" = 1,
...         "size" = {
...             "value" = 10,
...             "units" = 'inches'
...         }
...     }
... );
INSERT OK, 1 row affected  (... sec)
cr> INSERT INTO my_table (
...     title,
...     protagonist
... ) VALUES (
...     'Alice in Wonderland',
...     {
...         "name" = 'Alice',
...         "chapter" = 2,
...         "size" = 'As big as a room'
...     }
... );
INSERT OK, 1 row affected  (... sec)
cr> SELECT
...     protagonist['name'] as name,
...     protagonist['chapter'] as chapter,
...     protagonist['size'] as size
... FROM my_table
... ORDER BY protagonist['chapter'] ASC;
+-------+---------+----------------------------------+
| name  | chapter | size                             |
+-------+---------+----------------------------------+
| Alice |       1 | {"units": "inches", "value": 10} |
| Alice |       2 | As big as a room                 |
+-------+---------+----------------------------------+
SELECT 2 rows in set (... sec)

Reflecting the types of the columns:

cr> SELECT
...     pg_typeof(protagonist['name']) as name_type,
...     pg_typeof(protagonist['chapter']) as chapter_type,
...     pg_typeof(protagonist['size']) as size_type
... FROM my_table
... ORDER BY protagonist['chapter'] ASC;
+-----------+--------------+-----------+
| name_type | chapter_type | size_type |
+-----------+--------------+-----------+
| text      | smallint     | undefined |
| text      | smallint     | undefined |
+-----------+--------------+-----------+
SELECT 2 rows in set (... sec)

Note

Given that dynamically added sub-columns of an IGNORED object are not indexed, filter operations on these columns cannot utilize the index and instead a value lookup is performed for each matching row. This can be mitigated by combining a filter using the AND clause with other predicates on indexed columns.

Futhermore, values for dynamically added sub-columns of an IGNORED objects aren’t stored in a column store, which means that ordering on these columns or using them with aggregates is also slower than using the same operations on regular columns. For some operations it may also be necessary to add an explicit type cast because there is no type information available in the schema.

An example:

cr> SELECT
...     protagonist['name'] as name,
...     protagonist['chapter'] as chapter,
...     protagonist['size'] as size
... FROM my_table
... ORDER BY protagonist['size']::TEXT ASC;
+-------+---------+----------------------------------+
| name  | chapter | size                             |
+-------+---------+----------------------------------+
| Alice |       2 | As big as a room                 |
| Alice |       1 | {"units": "inches", "value": 10} |
+-------+---------+----------------------------------+
SELECT 2 rows in set (... sec)

Given that it is possible have values of different types within the same sub-column of an ignored objects, aggregations may fail at runtime:

cr> SELECT protagonist['size']::BIGINT FROM my_table ORDER BY protagonist['chapter'] LIMIT 1;
SQLParseException[Cannot cast value `{value=10, units=inches}` to type `bigint`]
Object literals

You can insert objects using object literals. Object literals are delimited using curly brackets and key-value pairs are connected via =.

Synopsis:

{ [ ident = expr [ , ... ] ] }

Here, ident is the key and expr is the value. The key must be a lowercase column identifier or a quoted mixed-case column identifier. The value must be a value literal (object literals are permitted and can be nested in this way).

Empty object literal:

{}

Boolean type:

{ my_bool_column = true }

Text type:

{ my_str_col = 'this is a text value' }

Number types:

{ my_int_col = 1234, my_float_col = 5.6 }

Array type:

{ my_array_column = ['v', 'a', 'l', 'u', 'e'] }

Camel case keys must be quoted:

{ "CamelCaseColumn" = 'this is a text value' }

Nested object:

{ nested_obj_colmn = { int_col = 1234, str_col = 'text value' } }

You can even specify a placeholder parameter for a value:

{ my_other_column = ? }

Combined:

{ id = 1, name = 'foo', tags = ['apple'], size = 3.1415, valid = ? }

Note

Even though they look like JSON, object literals are not JSON. If you want to use JSON, skip to the next subsection.

Inserting objects as JSON

You can insert objects using JSON strings. To do this, you must type cast the string to an object with an implicit cast (i.e., passing a string into an object column) or an explicit cast (i.e., using the ::OBJECT syntax).

Tip

Explicit casts can improve query readability.

Below you will find examples from the previous subsection rewritten to use JSON strings with explicit casts.

Empty object literal:

'{}'::object

Boolean type:

'{ "my_bool_column": true }'::object

Text type:

'{ "my_str_col": "this is a text value" }'::object

Number types:

'{ "my_int_col": 1234, "my_float_col": 5.6 }'::object

Array type:

'{ "my_array_column": ["v", "a", "l", "u", "e"] }'::object

Camel case keys:

'{ "CamelCaseColumn": "this is a text value" }'::object

Nested object:

'{ "nested_obj_col": { "int_col": 1234, "str_col": "foo" } }'::object

Note

You cannot use placeholder parameters inside a JSON string.

Arrays

ARRAY

An array is structured as a collection of other data types.

Arrays can contain the following:

Array types are defined as follows:

cr> CREATE TABLE my_table_arrays (
...     tags ARRAY(TEXT),
...     objects ARRAY(OBJECT AS (age INTEGER, name TEXT))
... );
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table_arrays (
...     tags,
...     objects
... ) VALUES (
...     ['foo', 'bar'],
...     [{"name" = 'Alice', "age" = 33}, {"name" = 'Bob', "age" = 45}]
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT * FROM my_table_arrays;
+----------------+------------------------------------------------------------+
| tags           | objects                                                    |
+----------------+------------------------------------------------------------+
| ["foo", "bar"] | [{"age": 33, "name": "Alice"}, {"age": 45, "name": "Bob"}] |
+----------------+------------------------------------------------------------+
SELECT 1 row in set (... sec)

An alternative is the following syntax to refer to arrays:

<typeName>[]

This means TEXT[] is equivalent to ARRAY(text).

Note

Nested arrays are not supported. Something like ARRAY(ARRAY(TEXT)) won’t work.

Arrays are always represented as zero or more literal elements inside square brackets ([]), for example:

[1, 2, 3]
['Zaphod', 'Ford', 'Arthur']
Array literals

Arrays can be written using the array constructor ARRAY[] or short []. The array constructor is an expression that accepts both literals and expressions as its parameters. Parameters may contain zero or more elements.

Synopsis:

[ ARRAY ] '[' element [ , ... ] ']'

All array elements must have the same data type, which determines the inner type of the array. If an array contains no elements, its element type will be inferred by the context in which it occurs, if possible.

Some valid arrays are:

[]
[null]
[1, 2, 3, 4, 5, 6, 7, 8]
['Zaphod', 'Ford', 'Arthur']
[?]
ARRAY[true, false]
ARRAY[column_a, column_b]
ARRAY[ARRAY[1, 2, 1 + 2], ARRAY[3, 4, 3 + 4]]

An alternative way to define arrays is to use string literals and casts to arrays. This requires a string literal that contains the elements separated by comma and enclosed with curly braces:

'{ val1, val2, val3 }'
cr> SELECT '{ab, CD, "CD", null, "null"}'::ARRAY(TEXT) AS arr;
+----------------------------------+
| arr                              |
+----------------------------------+
| ["ab", "CD", "CD", null, "null"] |
+----------------------------------+
SELECT 1 row in set (... sec)

null elements are interpreted as null (none, absent), if you want the literal null string, it has to be enclosed in double quotes.

This variant primarily exists for compatibility with PostgreSQL. The array constructor syntax explained further above is the preferred way to define constant array values.

Geographic types

Geographic types are types with nonscalar values representing points or shapes in a 2D world:

Geometric points

GEO_POINT

A GEO_POINT is a geographic data type used to store latitude and longitude coordinates.

To define a GEO_POINT column, use:

<columnName> GEO_POINT

Values for columns with the GEO_POINT type are represented and inserted using an array of doubles in the following format:

[<lon_value>, <lat_value>]

Alternatively, a WKT string can also be used to declare geo points:

'POINT ( <lon_value> <lat_value> )'

Note

Empty geo points are not supported.

Additionally, if a column is dynamically created, the type detection won’t recognize neither WKT strings nor double arrays. That means columns of type GEO_POINT must always be declared beforehand.

An example:

cr> CREATE TABLE my_table_geo (
...   id INTEGER PRIMARY KEY,
...   pin GEO_POINT
... ) WITH (number_of_replicas = 0)
CREATE OK, 1 row affected (... sec)

Insert using ARRAY syntax:

cr> INSERT INTO my_table_geo (
...     id, pin
... ) VALUES (
...     1, [13.46738, 52.50463]
... );
INSERT OK, 1 row affected (... sec)

Insert using WKT syntax:

cr> INSERT INTO my_table_geo (
...     id, pin
... ) VALUES (
...     2, 'POINT (9.7417 47.4108)'
... );
INSERT OK, 1 row affected (... sec)

Query data:

cr> SELECT * FROM my_table_geo;
+----+-----------------------------------------+
| id | pin                                     |
+----+-----------------------------------------+
|  1 | [13.467379929497838, 52.50462996773422] |
|  2 | [9.741699993610382, 47.410799972712994] |
+----+-----------------------------------------+
SELECT 2 rows in set (... sec)

Geometric shapes

GEO_SHAPE

A geo_shape is a geographic data type used to store 2D shapes defined as GeoJSON geometry objects.

A GEO_SHAPE column can store different kinds of GeoJSON geometry objects, namely “Point”, “MultiPoint”, “LineString”, “MultiLineString”, “Polygon”, “MultiPolygon”, and “GeometryCollection”.

Thus it is possible to store e.g. Point, LineString, and MultiPolygon shapes in the same column.

Caution

  • 3D coordinates are not supported.

  • Empty Polygon and LineString geo shapes are not supported.

An example:

cr> CREATE TABLE my_table_geo (
...   id INTEGER PRIMARY KEY,
...   area GEO_SHAPE
... ) WITH (number_of_replicas = 0)
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table_geo (
...     id, area
... ) VALUES (
...     1, 'POLYGON ((5 5, 10 5, 10 10, 5 10, 5 5))'
... );
INSERT OK, 1 row affected (... sec)
cr> SELECT * FROM my_table_geo;
+----+--------------------------------------------------------------------------------------------------------+
| id | area                                                                                                   |
+----+--------------------------------------------------------------------------------------------------------+
|  1 | {"coordinates": [[[5.0, 5.0], [5.0, 10.0], [10.0, 10.0], [10.0, 5.0], [5.0, 5.0]]], "type": "Polygon"} |
+----+--------------------------------------------------------------------------------------------------------+
SELECT 1 row in set (... sec)
Geo shape column definition

To define a GEO_SHAPE column, use:

<columnName> GEO_SHAPE

A geographical index with default parameters is created implicitly to allow for geographical queries. Its default parameters are:

<columnName> GEO_SHAPE INDEX USING geohash
    WITH (precision='50m', distance_error_pct=0.025)

There are two geographic index types: geohash (the default) and quadtree. These indices are only allowed on geo_shape columns. For more information, see Geo shape index structure.

Both of these index types accept the following parameters:

precision

(Default: 50m) Define the maximum precision of the used index and thus for all indexed shapes. Given as string containing a number and an optional distance unit (defaults to m).

Supported units are inch (in), yard (yd), miles (mi), kilometers (km), meters (m), centimeters (cm), millimeters (mm).

distance_error_pct

(Default: 0.025 (2,5%)) The measure of acceptable error for shapes stored in this column expressed as a percentage value of the shape size The allowed maximum is 0.5 (50%).

The percentage will be taken from the diagonal distance from the center of the bounding box enclosing the shape to the closest corner of the enclosing box. In effect bigger shapes will be indexed with lower precision than smaller shapes. The ratio of precision loss is determined by this setting, that means the higher the distance_error_pct the smaller the indexing precision.

This will have the effect of increasing the indexed shape internally, so e.g. points that are not exactly inside this shape will end up inside it when it comes to querying as the shape has grown when indexed.

tree_levels

Maximum number of layers to be used by the PrefixTree defined by the index type (either geohash or quadtree. See Geo shape index structure).

This can be used to control the precision of the used index. Since this parameter requires a certain level of understanting of the underlying implementation, users may use the precision parameter instead. CrateDB uses the tree_levels parameter internally and this is what is returned via the SHOW CREATE TABLE statement even if you use the precision parameter. Defaults to the value which is 50m converted to precision depending on the index type.

Geo shape index structure

Computations on very complex polygons and geometry collections are exact but very expensive. To provide fast queries even on complex shapes, CrateDB uses a different approach to store, analyze and query geo shapes.

The surface of the earth is represented as a number of grid layers each with higher precision. While the upper layer has one grid cell, the layer below contains many cells for the equivalent space.

Each grid cell on each layer is addressed in 2d space either by a Geohash for geohash trees or by tightly packed coordinates in a Quadtree. Those addresses conveniently share the same address-prefix between lower layers and upper layers. So we are able to use a Trie to represent the grids, and Tries can be queried efficiently as their complexity is determined by the tree depth only.

A geo shape is transformed into these grid cells. Think of this transformation process as dissecting a vector image into its pixelated counterpart, reasonably accurately. We end up with multiple images each with a better resolution, up to the configured precision.

Every grid cell that processed up to the configured precision is stored in an inverted index, creating a mapping from a grid cell to all shapes that touch it. This mapping is our geographic index.

The main difference is that the geohash supports higher precision than the quadtree tree. Both tree implementations support precision in order of fractions of millimeters.

Geo shape literals

Columns with the GEO_SHAPE type are represented and inserted as an object containing a valid GeoJSON geometry object:

{
    type = 'Polygon',
    coordinates = [
        [
            [100.0, 0.0],
            [101.0, 0.0],
            [101.0, 1.0],
            [100.0, 1.0],
            [100.0, 0.0]
        ]
    ]
}

Alternatively a WKT string can be used to represent a GEO_SHAPE as well:

'POLYGON ((5 5, 10 5, 10 10, 5 10, 5 5))'

Note

It is not possible to detect a GEO_SHAPE type for a dynamically created column. Like with GEO_POINT type, GEO_SHAPE columns need to be created explicitly using either CREATE TABLE or ALTER TABLE.

Geo shape GeoJSON examples

Those are examples showing how to insert all possible kinds of GeoJSON types using WKT syntax.

cr> CREATE TABLE my_table_geo (
...   id INTEGER PRIMARY KEY,
...   area GEO_SHAPE
... ) WITH (number_of_replicas = 0)
CREATE OK, 1 row affected (... sec)
cr> INSERT INTO my_table_geo (
...     id, area
... ) VALUES
...     (1, 'POINT (9.7417 47.4108)'),
...     (2, 'MULTIPOINT (47.4108 9.7417, 9.7483 47.4106)'),
...     (3, 'LINESTRING (47.4108 9.7417, 9.7483 47.4106)'),
...     (4, 'MULTILINESTRING ((47.4108 9.7417, 9.7483 47.4106), (52.50463 13.46738, 52.51000 13.47000))'),
...     (5, 'POLYGON ((47.4108 9.7417, 9.7483 47.4106, 9.7426 47.4142, 47.4108 9.7417))'),
...     (6, 'MULTIPOLYGON (((5 5, 10 5, 10 10, 5 5)), ((6 6, 10 5, 10 10, 6 6)))'),
...     (7, 'GEOMETRYCOLLECTION (POINT (9.7417 47.4108), MULTIPOINT (47.4108 9.7417, 9.7483 47.4106))')
... ;
INSERT OK, 7 rows affected (... sec)
cr> SELECT * FROM my_table_geo ORDER BY id;
+----+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | area                                                                                                                                                                               |
+----+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|  1 | {"coordinates": [9.7417, 47.4108], "type": "Point"}                                                                                                                                |
|  2 | {"coordinates": [[47.4108, 9.7417], [9.7483, 47.4106]], "type": "MultiPoint"}                                                                                                      |
|  3 | {"coordinates": [[47.4108, 9.7417], [9.7483, 47.4106]], "type": "LineString"}                                                                                                      |
|  4 | {"coordinates": [[[47.4108, 9.7417], [9.7483, 47.4106]], [[52.50463, 13.46738], [52.51, 13.47]]], "type": "MultiLineString"}                                                       |
|  5 | {"coordinates": [[[47.4108, 9.7417], [9.7483, 47.4106], [9.7426, 47.4142], [47.4108, 9.7417]]], "type": "Polygon"}                                                                 |
|  6 | {"coordinates": [[[[5.0, 5.0], [10.0, 5.0], [10.0, 10.0], [5.0, 5.0]]], [[[6.0, 6.0], [10.0, 5.0], [10.0, 10.0], [6.0, 6.0]]]], "type": "MultiPolygon"}                            |
|  7 | {"geometries": [{"coordinates": [9.7417, 47.4108], "type": "Point"}, {"coordinates": [[47.4108, 9.7417], [9.7483, 47.4106]], "type": "MultiPoint"}], "type": "GeometryCollection"} |
+----+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
SELECT 7 rows in set (... sec)

Type casting

A type CAST specifies a conversion from one data type to another. It will only succeed if the value of the expression is convertible to the desired data type, otherwise an error is returned.

CrateDB supports two equivalent syntaxes for type casts:

CAST(expression AS TYPE)
expression::TYPE

Cast expressions

CAST(expression AS TYPE)
expression::TYPE

Cast functions

CAST

Example usages:

cr> SELECT CAST(port['http'] AS BOOLEAN) AS col FROM sys.nodes LIMIT 1;
+------+
| col  |
+------+
| TRUE |
+------+
SELECT 1 row in set (... sec)
cr> SELECT (2+10)/2::TEXT AS col;
+-----+
| col |
+-----+
|   6 |
+-----+
SELECT 1 row in set (... sec)

It is also possible to convert array structures to different data types, e.g. converting an array of integer values to a boolean array.

cr> SELECT CAST([0,1,5] AS ARRAY(BOOLEAN)) AS active_threads ;
+---------------------+
| active_threads      |
+---------------------+
| [false, true, true] |
+---------------------+
SELECT 1 row in set (... sec)

Note

It is not possible to cast to or from OBJECT, GEO_POINT, and GEO_SHAPE types.

TRY_CAST

While CAST throws an error for incompatible type casts, TRY_CAST returns null in this case. Otherwise the result is the same as with CAST.

TRY_CAST(expression AS TYPE)

Example usages:

cr> SELECT TRY_CAST('true' AS BOOLEAN) AS col;
+------+
| col  |
+------+
| TRUE |
+------+
SELECT 1 row in set (... sec)

Trying to cast a TEXT to INTEGER, will fail with CAST if TEXT is no valid integer but return null with TRY_CAST:

cr> SELECT TRY_CAST(name AS INTEGER) AS name_as_int FROM sys.nodes LIMIT 1;
+-------------+
| name_as_int |
+-------------+
|        NULL |
+-------------+
SELECT 1 row in set (... sec)

Cast from string literals

This cast operation is applied to a string literal and it effectively initializes a constant of an arbitrary type.

Example usages, initializing an INTEGER and a TIMESTAMP constant:

cr> SELECT INTEGER '25' AS int;
+-----+
| int |
+-----+
|  25 |
+-----+
SELECT 1 row in set (... sec)
cr> SELECT TIMESTAMP WITH TIME ZONE '2029-12-12T11:44:00.24446' AS ts;
+---------------+
| ts            |
+---------------+
| 1891770240244 |
+---------------+
SELECT 1 row in set (... sec)

Note

This cast operation is limited to primitive data types only. For complex types such as ARRAY or OBJECT, use the Cast functions syntax.

PostgreSQL compatibility

Type aliases

For compatibility with PostgreSQL we include some type aliases which can be used instead of the CrateDB specific type names.

For example, in a type cast:

cr> SELECT 10::INT2 AS INT2;
+------+
| int2 |
+------+
|   10 |
+------+
SELECT 1 row in set (... sec)

See the table below for a full list of aliases:

Alias

CrateDB Type

SHORT

SMALLINT

INT

INTEGER

INT2

SMALLINT

INT4

INTEGER

INT8

BIGINT

LONG

BIGINT

STRING

TEXT

VARCHAR

TEXT

CHARACTER VARYING

TEXT

NAME

TEXT

REGPROC

TEXT

BYTE

CHAR

FLOAT

REAL

FLOAT4

REAL

FLOAT8

DOUBLE PRECISION

DOUBLE

DOUBLE PRECISION

TIMESTAMP

TIMESTAMP WITH TIME ZONE

TIMESTAMPTZ

TIMESTAMP WITH TIME ZONE

Note

The PG_TYPEOF system function can be used to resolve the data type of any expression.

Internal-use types

CHAR

A one-byte character used internally for enumeration items in the PostgreSQL system catalogs.

Specified as a signed integer in the range -128 to 127.

OID

An Object Identifier (OID). OIDS are used internally as primary keys in the PostgreSQL system catalogs.

The OID type is mapped to the integer data type.

REGPROC

An alias for the oid type.

The REGPROC type is used by tables in the pg_catalog schema to reference functions in the pg_proc table.

Casting a REGPROC type to a TEXT or integer type will result in the corresponding function name or oid value, respectively.

REGCLASS

An alias for the oid type.

The REGCLASS type is used by tables in the pg_catalog schema to reference relations in the pg_class table.

Casting a REGCLASS type to a TEXT or integer type will result in the corresponding relation name or oid value, respectively.

OIDVECTOR

The OIDVECTOR type is used to represent one or more oid values.

This type is similar to an array of integers. However, you cannot use it with any scalar functions or expressions.

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