Documentation

Miscellaneous SQL functions

The InfluxDB 3 Core SQL implementation supports the following miscellaneous functions for performing a variety of operations:

arrow_cast

Casts a value to a specific Arrow data type.

arrow_cast(expression, datatype)

Arguments

  • expression: Expression to cast. Can be a constant, column, or function, and any combination of arithmetic or string operators.
  • datatype: Arrow data type to cast to.

View arrow_cast query example

arrow_typeof

Returns the underlying Arrow data type of the expression:

arrow_typeof(expression)

Arguments

  • expression: Expression to evaluate. Can be a constant, column, or function, and any combination of arithmetic or string operators.

View arrow_typeof query example

get_field

Returns a field from a map or a struct with the specified key.

Typically, get_field is indirectly invoked via field access syntax such as my_struct['field_name'] which results in the call: get_field(my_struct, 'field_name').

get_field(collection, field)

Arguments

  • collection: The map or struct to retrieve a field from.
  • field: The name of field the field to retrieve from the map or struct. Must evaluate to a string.

View get_field example with a struct column

View get_field example with a map column

interpolate

Fills null values in a specified aggregated column by interpolating values from existing values. Must be used with date_bin_gapfill.

interpolate(aggregate_expression)

Arguments

  • aggregate_expression: Aggregate operation on a specified expression. The operation can use any aggregate function. The expression can be a constant, column, or function, and any combination of arithmetic operators supported by the aggregate function.

date_bin_gapfill, locf

View interpolate query example

locf

Fills null values in a specified aggregated column by carrying the last observed value forward. Must be used with date_bin_gapfill.

LOCF is an initialism of “last observation carried forward.”

locf(aggregate_expression)

Arguments

  • aggregate_expression: Aggregate operation on a specified expression. The operation can use any aggregate function. The expression can be a constant, column, or function, and any combination of arithmetic operators supported by the aggregate function.

date_bin_gapfill, interpolate

View locf query example

version

Returns the version of DataFusion.

version()

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New in InfluxDB 3.5

Key enhancements in InfluxDB 3.5 and the InfluxDB 3 Explorer 1.3.

See the Blog Post

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InfluxDB Docker latest tag changing to InfluxDB 3 Core

On November 3, 2025, the latest tag for InfluxDB Docker images will point to InfluxDB 3 Core. To avoid unexpected upgrades, use specific version tags in your Docker deployments.

If using Docker to install and run InfluxDB, the latest tag will point to InfluxDB 3 Core. To avoid unexpected upgrades, use specific version tags in your Docker deployments. For example, if using Docker to run InfluxDB v2, replace the latest version tag with a specific version tag in your Docker pull command–for example:

docker pull influxdb:2