> For the complete documentation index, see [llms.txt](https://olddocs.exivity.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://olddocs.exivity.io/3.4.3/data-pipelines/transform/language/default.md).

# 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](/3.4.3/data-pipelines/transform/language/create.md). A column name in a Transcript statement is assumed as belonging to the default DSET unless it is a [fully qualified](/3.4.3/advanced/digging-deeper/dataset-lifecycle.md) column name.

If there is no `default` statement in the Transcript, then the first CSV file imported via the [import](/3.4.3/data-pipelines/transform/language/import.md) 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](/3.4.3/data-pipelines/transform/language/finish.md) 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](/3.4.3/data-pipelines/transform/language/service.md) 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`