BI-as-code ?

Before diving into the different tools, it's important to understand why such tools are emerging. Data engineering has seen significant advancements, yet the rest of the analytics chain often hasn't kept pace.

Typically, business and analytics users extract data from a data warehouse and build their dashboards using WYSIWYG tools such as Tableau, PowerBi, or Excel.

What's the issue with these tools? They were designed with a user interface-first focus to lower the technical barrier to entry. However, this approach can lead to increased technical debt.

For instance, how do you roll back a UI dashboard or prevent it from breaking? Ultimately, the dashboard that presents your Key Performance Indicators (KPIs) is a software asset.

Let's consider what some tools offer today, along with their advantages (remember, the choice is yours). They all share some common features:

• Open-source nature
• Paid or managed services for hosting
• BI as a code approach, allowing for versioning and testing through standard CI pipelines
• Compatibility with both DuckDB and MotherDuck

The New Kids in Town

So how are these quacking ? 🦆

Let's come back to our use case to analyze PyPi statistics on the Python package of duckdb. I won't go into the complete code example, but I'll put some beautiful screenshots and code snippets to grasp how each one works. Feel free to follow along with the source code for the dashboards below.

Evidence

Setup

To quickly start an evidence project, you essentially need to copy a JS template. You can do this either by using Node.js and degit package or their container image using the devcontainer feature from VSCode.

According to their documentation, here's how you can do it:

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npx degit evidence-dev/template my-project
cd my-project
npm install
npm run dev

Project structure & Connection to DuckDB

There are 3 main important part in the projects

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.evidence               // evidence configurations
pages/index.md          // Where we write .md & SQL
evidence.plugins.yaml   // configure evidence plugins

Once the local server is running, you can connect to DuckDB through the UI settings page.

For a local DuckDB database, you will just need to provide the path and the extension.

For a MotherDuck database, you will need to specify your MotherDuck Token. More information about how to retrieve this token and work in production on our documentation.

Creating Visualizations

Evidence renders markdown files into web pages. When developing, the markdown file /pages/example.md is rendered at localhost:3000/example.

Evidence has a collection of components that you can use for your visualization. You then defined your SQL query attached to this component.

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<BigValue
    title='Total download past 2 years'
    data={total_count}
    value='download_count'
    fmt='#,##0.00,,"M"'
/>
```total_count
SELECT SUM(daily_download_count) AS download_count
FROM daily_stats
WHERE timestamp_day BETWEEN DATE_TRUNC('month', CURRENT_DATE) AND CURRENT_DATE;

This would display :

That sums up how you can create your components. Of course, there's more to it, such as reusing SQL queries, filters, etc.

Deployment

When you generate a static website, you have the flexibility to host it anywhere that supports JS static websites. Evidence also provides its own cloud service to streamline the deployment process from local to production.

Rill

Setup

Rill provides a Command Line Interface (CLI), essentially a binary (written in Golang) for installation. There's a single command line that executes the installation for you.

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curl -s <https://cdn.rilldata.com/install.sh> | bash

rill should then be then available in your terminal

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Usage:
  rill [command]

Available Commands:
  start          Build project and start web app
  docs           Open docs.rilldata.com
  version        Show Rill version
  upgrade        Upgrade Rill to the latest version
  whoami         Show current user
  org            Manage organisations
  project        Manage projects
  deploy         Deploy project to Rill Cloud
  user           Manage users
  env            Manage variables for a project
  login          Authenticate with the Rill API
  logout         Logout of the Rill API
  help           Help about any command

Flags:
  -h, --help          Print usage
      --interactive   Prompt for missing required parameters (default true)
  -v, --version       Show rill version

Use "rill [command] --help" for more information about a command.

Project structure & Connection to DuckDB

To start a fresh new project, you can do :

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rill start my-rill-project

When you start a project, it launches a local server. When you browse to the page, you will see the following:

If you click on any of these examples, it will generate .yaml and .sql files and there are 3 main folders :

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├── dashboards 
│   └── customer_margin_dash.yaml
├── models
│   └── metrics_margin_model.sql
├── rill.yaml
├── sources
│   └── metrics_margin_monitoring.yaml

In sources, you define any supported sources using YAML. Models contain SQL queries that will be used in your dashboard, and dashboard is where you specify your metrics, in YAML. You can also edit these through the Rill UI.

Coming back to our PyPI stats use case, since we have a DuckDB database containing the data, we can proceed as follows:

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rill start rill/my-rill-project --db rill/data/duckdb_stats.db

To connect to MotherDuck, you would need to export motherduck_token as an environment variable. More information on their documentation here.

There's a small workaround to do : it won't be displayed as a source table in the Rill UI.

However, we can create a model in the models folder as described below or directly use it in the dashboard.

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select * from duckdb_stats.main.daily_stats

We can now define some metrics in our model_dashboard.yaml

The overarching goal of Rill is to provide you with a tailored dashboard based on the metrics you want to see, rather than offering an endless collection of charts that you have to construct yourself.

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title: Pypi Download Stats
model: model
timeseries: timestamp_day
measures:
  - label: Total Downloads
    expression: sum(daily_download_count)
    name: total_records
    description: Total number of records present
    format_preset: humanize
    valid_percent_of_total: true
dimensions:
  - name: python_version
    label: Python_version
    column: python_version
    description: ""
  - name: system_name
    label: System_name
    column: system_name
    description: ""
  - name: cpu
    label: Cpu
    column: cpu
    description: ""
  - name: file_version
    label: File_version
    column: file_version
    description: ""
  - name: country
    label: Country
    column: country
    description: ""

Deployment

Deployment is done through Rill’s Cloud offering. It’s worth to mention that compared to the other solutions, Rill offer users access management out of the box.

Streamlit

Setup

For someone familiar with Python, getting started with Streamlit is quite simple. All you need is a Python environment and common packages like streamlit, duckdb, pandas, and matplotlib for data visualization.

Running the app, as per our example is as simple as :

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streamlit run app.py

Project structure & Connection to DuckDB/MotherDuck

You have the freedom to structure your Python app as you see fit. However, for beginners, everything can be contained in a single script.

Connecting to DuckDB/MotherDuck is the standard Python way.

For a local connect to our PyPi stats DuckDB database, use the following:

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import duckdb
con = duckdb.connect(database='duckdb_stats.db', read_only=True)

To connect to MotherDuck, you will have to provide your token :

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import duckdb
con = duckdb.connect('md:?motherduck_token=<token>')

Creating Visualizations

Streamlit offers a vast array of components, including interactive features for audio/video or LLMs, among others. We're only scratching the surface here.

The primary strategy involves using a Pandas dataframe and using the built-in charts that Streamlit provides.

Let’s build the Pandas dataframe first :

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# Query for filtered data
query = """
SELECT 
    DATE_TRUNC('month', timestamp_day) AS month, 
    SUM(daily_download_count) AS total_downloads,
    python_version,
    cpu
FROM duckdb_stats.main.daily_stats
WHERE timestamp_day BETWEEN ? AND ?
GROUP BY month, python_version, cpu
ORDER BY month
"""
df = con.execute(query, (start_date, end_date)).df()

DuckDB supports natively conversion of results to Pandas dataframe.

And our first chart :

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# Line Graph of Downloads Over Time
st.subheader("Monthly Downloads Over Time")
df_monthly = df.groupby('month')['total_downloads'].sum().reset_index()
st.line_chart(df_monthly.set_index('month'))

Deployment

Streamlit offers a community Cloud where you can deploy your app for free. Since it's a python app, it can work on any python runtime that allows you to expose a web service.

The future of BI

Through the blog, we've explored three different tools that each offer a unique approach to BI-as-code.

You can conduct all tests locally and use Git for version control and CI/CD. Your dashboard can be easily deployed or rolled back, all while embracing software best practices. BI doesn't have to be a tedious click-through expensive UI. It's refreshing to see new perspectives. Even though some of these tools are in their early stages, they show great promise.

Stay tuned for our next blog post, where we'll dive into how to efficiently collect data from PyPI into DuckDB. This will enable you to easily build your own PyPI stats dashboard for your Python project!

Keep coding, keep quacking.