---
title: "Creating Datasets: The Preset Semantic Layer"
slug: "creating-datasets"
updated: 2022-10-20T21:19:35Z
published: 2022-10-20T21:19:35Z
canonical: "docs.preset.io/creating-datasets"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.preset.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Creating Datasets: The Preset Semantic Layer

## Datasets: The Foundation of Visualizations

If your Admin has already connected your organization's database, then you are almost ready to start creating stunning data-driven charts and dashboards.

There is, however, one key step remaining: adding a [physical dataset](/v1/docs/physical-datasets) or a [virtual dataset](/v1/docs/virtual-datasets).

Datasets are curated representation of data in your database, allowing charts you want to create to have unified metric definitions. They are a critical component, as every chart is created from a dataset. Datasets offer a high level of flexibility in modeling data you've collected, enabling your organization to take then determine how information is presented to specific audiences in a chart or dashboard.

In this article, we will look at how Preset works with your data and answer some common questions about datasets.

We encourage you to read [Physical Datasets](/v1/docs/physical-datasets) and [Virtual Datasets](/v1/docs/virtual-datasets) to learn more about how to add these two dataset types.

---

## Key Points: Preset and your Data

- Preset doesn't extract data from your database.
- All storage and computation occurs on your existing backend.
- A Preset dataset is a curated representation of data already in your database.
- Every chart is based on a dataset.

---

## What is a dataset?

  

A dataset is a Preset abstraction that points to data in your database. This data is used to create charts in Preset.

---

## Dataset Questions & Answers

### Why datasets? Why not a pure query-centric approach?

Datasets offer an agreed source of truth for metric definitions — all charts that are built from a single dataset utilize the same set of comprehensive collection of relevant dimensions and metrics.

Datasets further enables users to self-serve within this safe "dimensional" playground. Your team members can typically slice and dice, apply arbitrary filters, and drill into dimensional details — all without altering pre-determined definitions of certain metrics.

This is superior to a pure query-centric approach (i.e., one-query-one-chart), where “pivoting” and slice-and-dicing requires going back to the query, understanding semantics of certain columns or metrics, and updating a query to fit your next question. Oftentimes a query-centric approach create multiple interpretations of the same metric.

### Do I need to add a dataset?

In short, yes. Adding a dataset enables you to create new charts and, consequently, dashboards.

### What are the benefits of datasets?

Datasets can be customized to align with your unique audience, such as defining availability of field data, specifying date formats, and changing labels.

### How do I add a dataset?

Please see [Physical Datasets](/v1/docs/physical-datasets) or [Virtual Datasets](/v1/docs/virtual-datasets) to learn about the process for each dataset type.

### Can datasets be further customized?

Yes. Preset's [semantic layer](/v1/docs/semantic-layer) enables you to modify a dataset's metrics, columns, and create calculated columns.

### How do I use a dataset?

The primary purpose of a dataset is to enable you to create a chart. You can create a chart in one of two ways:

1. Use the [Chart Gallery](/v1/docs/creating-a-chart#choose-a-dataset) screen to select a dataset and a chart type, and then [configure](/v1/docs/creating-a-chart#configure-the-chart) a chart; or,

![Choose_a_Dataset_Option_Create_a_Chart](https://cdn.document360.io/4749ddf8-aa05-4f3f-80e1-07a5d2d0f137/Images/Documentation/Choose_a_Dataset_Option_Create_a_Chart.png)

1. Select a dataset from the *Datasets* screen and use the [Explore](https://portal.document360.io/v1/docs/using-preset-explore) interface to configure a chart.

![Select_Dataset_from_List](https://cdn.document360.io/4749ddf8-aa05-4f3f-80e1-07a5d2d0f137/Images/Documentation/Select_Dataset_from_List.png)

Please see [Chart Examples](/v1/docs/chart-walkthroughs#chart-examples) to see some of the more popular chart types available in Preset.