# union¶

Type of operation: Join

## Description¶

Create a new event dataset, consisting of events from two or more datasets, where the datasets are mapped onto the shape of the main input through column name matching, and filling in with NULL for mismatched column names. The event time column does not need to be explicitly mapped. It is an error to map columns of different types to the same name.

## Usage¶

union dataset ...


Argument

Type

Required

Multiple

dataset

datasetref

Required

Can be multiple

## Accelerable¶

union is always accelerable if the input is accelerable. A dataset that only uses accelerable verbs, can be accelerated, making queries on the dataset respond faster.

## Examples¶

union @second, @third


Create a new dataset that is the union of the main input dataset, and the @second and @third datasets, where names that are not shared are given NULL values in the opposite dataset.