FAQ

Do I need to whitelist IP addresses? Where do I find them?

Yes, if your PostgreSQL database is behind a firewall (AWS RDS, Azure, on-premise, etc.), you must whitelist Coupler.io's IP addresses. When you create a PostgreSQL connection in Coupler.io, the connection dialog displays the exact IPs to whitelist. Add these IPs to:

• AWS RDS: Modify the security group's inbound rules; add port 5432.

• Azure: Add firewall rules in the Azure portal.

• Self-hosted/On-premise: Update your network firewall or PostgreSQL's pg_hba.conf file.

Without whitelisting, you'll see "Connection refused" or "No route to host" errors.

Can I import from a Table or View, or do I need to write SQL?

You have two options:

1. Table or View — Select a schema and table name from a dropdown. Coupler.io imports all data from that table or view.

2. Custom SQL — Write a SQL query to filter, join, aggregate, or transform data before import.

Start with "Table or View" for simple imports. Use "Custom SQL" if you need filtering, joins, or aggregation.

What if my query is slow or times out?

If your data flow exceeds 30 seconds, Coupler.io will time out. To fix this:

1. Add a date filter to reduce rows: WHERE created_at >= NOW() - INTERVAL '90 days'

2. Use aggregation instead of SELECT *: SELECT user_id, COUNT(*) FROM orders GROUP BY user_id

3. Add indexes to columns in your WHERE clause: CREATE INDEX idx_created_at ON orders(created_at);

4. Remove unnecessary columns: Select only what you need.

Test your query in psql first to see how long it takes. If it's slow there, optimize it before adding to Coupler.io.

Can I join data from PostgreSQL with data from other sources?

Yes! In Coupler.io, you can use the Join transformation to combine PostgreSQL data with data from other sources (Google Ads, Facebook Ads, Stripe, etc.). For example, join customer data from PostgreSQL with revenue data from Stripe on a common ID. You can also use the Append transformation to combine data from multiple PostgreSQL tables or data flows.

What permissions does my database user need?

Your database user needs SELECT permission on the tables or views you're importing. To grant this:

GRANT SELECT ON table_name TO username;
GRANT USAGE ON SCHEMA schema_name TO username;

Do NOT grant INSERT, UPDATE, DELETE, or DROP permissions. Coupler.io only reads data.

Can I schedule data flow refreshes automatically?

Yes! After your first successful manual run, you can schedule the data flow to refresh on a daily, weekly, or custom schedule. In the data flow settings, choose your refresh frequency. Coupler.io will automatically run the import at the scheduled time and update your destination (Google Sheets, BigQuery, etc.).

Why am I getting a "Too much data" error?

Your query returns too many rows or columns to import at once. To fix this:

1. Filter by date: WHERE created_at >= NOW() - INTERVAL '30 days'

2. Select fewer columns: Instead of SELECT *, list specific columns.

3. Aggregate data: Use GROUP BY to reduce row count.

4. Split into multiple flows: Import different date ranges or tables separately, then Append them in Coupler.io.

Test your query in psql and check the row count: SELECT COUNT(*) FROM table WHERE ...;

Can I send PostgreSQL data to AI destinations like Claude or ChatGPT?

Yes! Coupler.io supports AI destinations including Claude, ChatGPT, Cursor, Gemini, Perplexity, and OpenClaw. Create a data flow that imports PostgreSQL data to an AI destination, and you can automatically generate insights, summaries, or reports from your database. For example, query weekly sales data from PostgreSQL and send it to Claude to generate a trend analysis.

What happens if my database password changes?

Your data flows will fail with an "Authentication failed" error. Update the password in the PostgreSQL connection settings:

1. In Coupler.io, go to Connections and find your PostgreSQL connection.

2. Click Edit and update the password.

3. Run a manual test to confirm the new credentials work.

4. Your scheduled data flows will resume on the next refresh.

Can I export data from multiple PostgreSQL databases in one data flow?

Each data flow has one primary source (one PostgreSQL database). However, you can create multiple data flows (one per database) and use the Append transformation to combine them into a single destination. For example, append sales data from PostgreSQL prod and PostgreSQL staging into one Google Sheet.

For connection and IP whitelisting details, see the Connection issues section. For performance optimization and slow query fixes, see Performance optimization.