> 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/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](/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](/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](/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](/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](broken://pages/-LfOfNlyxCrBu4uy0HDg) 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`


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://olddocs.exivity.io/data-pipelines/transform/language/default.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.