Connection to PostgreSQL

To connect a PostgreSQL database to the DQC Platform, you'll need to provide user credentials, access details, and optionally define the schema. This guide also outlines best practices for secure authentication.

Add a PostgreSQL connector

To get started:

Go to the Data Connectors screen
Click the PostgreSQL button
Enter the required connection details (see below)

Select PostgreSQL to begin setting up your connection

Required connection information

Field	Example	Description
Name	`Finance_DB`	A descriptive name for this connection
User	`dqcreader`	PostgreSQL user with read-only access
Password	`your_password_here`	Password for the specified user
Host	`db.company.internal`	DNS or IP address of the PostgreSQL server
Port	`5432`	Default PostgreSQL port (adjust if needed)
Database name	`company_data`	Target PostgreSQL database
Schema	`public` (optional)	Name of the schema to query (optional filter)

Best practices for secure authentication

Use a dedicated user

Avoid using administrative or shared credentials
Create a dedicated technical user for the DQC Platform

Grant read-only permissions

Limit access by assigning only the SELECT privilege. For example:

GRANT CONNECT ON DATABASE company_data TO dqcreader;
GRANT USAGE ON SCHEMA public TO dqcreader;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO dqcreader;

Whitelist the DQC Platform IP address

Ensure the following IP address is allowed by your PostgreSQL access rules (e.g., in pg_hba.conf, security groups, or firewall settings):

3.123.94.228

Troubleshooting

When DQC cannot connect to PostgreSQL or load its tables, it shows the reason with a short fix and links to this section. Look up the beginning of the message:

Message in DQC	Likely cause	Fix
`Wrong password for user …`	The password is wrong, or the user does not exist (PostgreSQL reports both the same way)	Check user name and password of the technical user
`User … does not exist`	The role does not exist or may not log in	Check the user name; the role needs the `LOGIN` attribute
`Database … does not exist`	Wrong database name, or the name was created in quotes with a different case	Enter the database name exactly as it is stored
`Connection to …:… not possible`	DQC cannot reach the server: wrong host or port, or a firewall or security group blocks the DQC IP address	Check host and port, whitelist the DQC Platform IP address, or connect through the DQC Proxy
`Unable to connect to Postgres database. Reason: … no pg_hba.conf entry …`	The server does not accept connections from the DQC IP address	Add the DQC Platform IP address to `pg_hba.conf` or to the firewall rules of your managed database
`Unable to connect to Postgres database. Reason: permission denied to create temporary tables …`	DQC reads query results through temporary views	Grant `TEMP` on the database: `GRANT TEMP ON DATABASE company_data TO dqcreader;`
`Unable to connect to Postgres database. Reason: … read-only transaction`	The host is a read replica	Connect to the primary server
`The provided schema does not exist …`	The schema name is wrong or has a different case	Enter the schema exactly as it is stored; unquoted names are lowercase
`Could not connect to the data source. Check the connection details …`	DQC could not classify the error of the connection test	Check every field of the form, the network access and the permissions described above
`Table not accessible anymore …`	The table was renamed, moved or deleted, or the user lost access to it after the last sync	Restore the table or the access, then resync the connector
`Technical user is not allowed to create virtual tables …`	Virtual tables need temporary tables in the source	Allow the user to create temporary tables, or do not use virtual tables on this connector

Synchronization failed: when a sync cannot connect, the connector shows Failed on the Data sources screen and the badge links to this section. Edit the connector and click Load tables or Save: DQC tests the connection again and shows the current reason.
Tables missing from the table list: DQC lists only tables the user can read. Grant USAGE on the schema and SELECT on the tables (see Grant read-only permissions).
Still stuck? Write to support@dqc.ai with the connector name, the time of the attempt and the full message.

Notes

Encrypted SSL connections are strongly recommended
For managed PostgreSQL (e.g. AWS RDS, Azure Database), whitelist the IP in your cloud firewall rules
Learn more: Supported data source s, Connection to Snowflake, Data source access permissions