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

# Data Sources overview

> Connect your data warehouse or database to Vero to build audiences directly from your customer data.

Data Sources let you connect Vero directly to your database or data warehouse. Once connected, you can write SQL queries to select customers and use the results as audiences for your campaigns.

## Why use Data Sources?

* **Query your existing data** — Build audiences from customer data already in your database without importing CSVs or syncing data manually.
* **Stay up to date** — For recurring campaigns, Vero re-runs your query on each send to ensure your audience reflects the latest data.
* **Full SQL flexibility** — Write custom queries to target exactly the customers you need.

## Supported databases

Vero supports the following databases and data warehouses:

<CardGroup cols={2}>
  <Card title="Snowflake" icon="snowflake" href="/vero-2/data-sources/how-to-connect-to-snowflake">
    Connect using RSA key authentication
  </Card>

  <Card title="Google BigQuery" icon="google" href="/vero-2/data-sources/how-to-connect-to-google-bigquery">
    Connect using a service account
  </Card>

  <Card title="PostgreSQL" icon="database" href="/vero-2/data-sources/how-to-connect-to-postgresql">
    Connect with username and password
  </Card>

  <Card title="MySQL" icon="database" href="/vero-2/data-sources/how-to-connect-to-mysql">
    Connect with username and password
  </Card>

  <Card title="Amazon Redshift" icon="aws" href="/vero-2/data-sources/how-to-connect-to-redshift">
    Connect with username and password
  </Card>

  <Card title="Microsoft SQL Server" icon="microsoft" href="/vero-2/data-sources/how-to-connect-to-microsoft-sql-server">
    Connect using SQL Server Authentication
  </Card>
</CardGroup>

## Security

Vero only executes read-only `SELECT` queries against your database. We recommend:

* Creating a dedicated read-only user for Vero
* Limiting access to only the tables and columns you need for campaigns
* Whitelisting Vero's IP addresses in your firewall

Each database guide includes specific security recommendations.

## Query limits

* Results display in pages of 100 rows in the audience UI
* No strict row limit — tested reliably up to 1 million rows
* Queries timeout after 12 hours