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

# Connections FAQ

> Frequently asked questions about connecting data sources.

Find quick answers to the most common setup, access, and sync questions.

<Tip>
  If your connection is failing, review the checklist in the troubleshooting guide first, then return here for specific scenarios.
</Tip>

## Quick answers

<AccordionGroup>
  <Accordion title="Can I connect to a database behind a VPN or private network?">
    Dex needs direct network access. If your database is in a private VPC, set up a bastion host, VPN tunnel, or make it publicly accessible with IP allowlisting.
  </Accordion>

  <Accordion title="What permissions does the database user need?">
    At minimum, the user needs `SELECT` permission on all schemas and tables Dex should analyze. Dex never writes to or modifies your data.
  </Accordion>

  <Accordion title="How is my data secured?">
    Credentials are encrypted with AES-256 before storage. Connections use SSL/TLS when available.
  </Accordion>

  <Accordion title="Can I change enabled resources or tables after connecting?">
    Yes. Update enabled resources from the connection settings in your dashboard at any time.
  </Accordion>

  <Accordion title="What happens during schema sync?">
    Dex discovers tables and collections, reads column definitions, and generates human-readable descriptions to help translate natural language into queries.
  </Accordion>

  <Accordion title="How often is the schema refreshed?">
    Schema sync runs when you first connect. You can manually trigger a re-sync from connection settings whenever your schema changes.
  </Accordion>
</AccordionGroup>