# default

## Overview

The `default` statement is used to explicitly define the default DSET to use when specifying a column name as an argument in subsequent statements.

## Syntax

**`default dset`***`source.alias`*

## Details

Given that multiple DSETS can be loaded at once, it is necessary to specify which DSET to operate on when performing actions such as creating a new column with [create](https://olddocs.exivity.io/3.5.4/data-pipelines/transform/language/create). A column name in a Transcript statement is assumed as belonging to the default DSET unless it is a [fully qualified](https://olddocs.exivity.io/3.5.4/advanced/digging-deeper/dataset-lifecycle) column name.

If there is no `default` statement in the Transcript, then the first CSV file imported via the [import](https://olddocs.exivity.io/3.5.4/data-pipelines/transform/language/import) statement will automatically be designated as the default DSET.

The `default` statement can be used multiple times throughout a Transcript, in which case the default DSET will be whichever was specified by the last `default` statement executed.

Lastly, when executing a [finish](https://olddocs.exivity.io/3.5.4/data-pipelines/transform/language/finish) statement, unless otherwise specified, the default DSET will be used to populate the reporting database created as a result.

{% hint style="info" %}
When changing the default DSET, any [service](https://olddocs.exivity.io/3.5.4/data-pipelines/transform/language/broken-reference) definitions that referenced the default DSET at the time they were created will be updated with the new default DSET.
{% endhint %}

## Examples

Set *custom.datafile* as the default DSET:

`default dset custom.datafile`