Configuring Redshift / PostgreSQL Access

This article will describe how to configure a Redshift or Data Warehouse credentials for use by Census, and why those permissions are needed.

Required Permissions

Census reads data from one or more tables (possibly across different schemata) in your database and publishes it to the corresponding objects in external systems such as Salesforce. To limit the load on your database as well as to other apps' APIs, Census computes a “diff” to determine changes between each update. In order to compute these diffs, Census creates and writes to a set of tables to a private bookkeeping schema (2 or 3 tables for each sync job configured).

We recommend you create a dedicated CENSUS user account with a strong, unique password. Census uses this account to connect to your Redshift or PostgreSQL database. In order for the Census connection to work correctly, the CENSUS account must have these permissions:

  • The ability to create the CENSUS schema and full admin access to all tables within that schema (including creating tables, deleting tables, and reading and writing to all tables).
  • Read-only access to any tables and views in any schemata that you would like Census to publish to your service destinations.
  • If you are using Census to load service data into your warehouse, read-write access to the schema where Census should load data (note that this is not included in the sample script below).

PostgreSQL and Redshift permissions are complex and there are many ways to configure access for Census. The script below has been tested with Redshift and recent PostgreSQL versions and is known to work correctly:

-- Give the census user the ability to sign in with a password
CREATE USER CENSUS WITH PASSWORD '<strong, unique password>';

-- Create a private bookkeeping schema where Census can store sync state
CREATE SCHEMA CENSUS;

-- Give the census user full access to the bookkeeping schema
GRANT ALL ON SCHEMA CENSUS TO CENSUS;

-- Ensure the census user has access to any objects that may have already existed in the bookkeeping schema
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA CENSUS TO CENSUS;

-- Let the census user see this schema
GRANT USAGE ON SCHEMA "<your schema>" TO CENSUS;

-- Let the census user read all existing tables in this schema
GRANT SELECT ON ALL TABLES IN SCHEMA "<your schema>" TO CENSUS;

-- Let the census user read any new tables added to this schema
ALTER DEFAULT PRIVILEGES IN SCHEMA "<your schema>" GRANT SELECT ON TABLES TO CENSUS;

-- Let the census user execute any existing functions in this schema
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA "<your schema>" TO CENSUS;

-- Let the census user execute any new functions added to this schema
ALTER DEFAULT PRIVILEGES IN SCHEMA "<your schema>" GRANT EXECUTE ON FUNCTIONS TO CENSUS;

Notes:

  • If you have multiple schemata that you would like Census to read from, repeat the steps for "<your schema>" for each of them
  • In Redshift and older versions of PostgreSQL, if there are views in your schema that reference tables in other schemata, you will also need to give Census read access to those other schemata. In later versions of PostgreSQL this extra read access is not required.
  • If you are using Census models to execute stored procedures (this is rare and not recommended for most users) you may also need to give Census access to those procedures

Encryption

All connections from the Census Data Warehouse Service to your database, as well as connections from your Redshift database to S3, are protected by TLS encryption - Census will refuse to connect to a warehouse that does not support TLS. All Census data stored in S3 is encrypted with AWS Server-Side Encryption (SSE). We recommend configuring your PostgreSQL instance to use TLS v1.2 or later for all connections.

Allowed IP Addresses

Census will always connect to your data warehouse from of these static IP addresses located within AWS:

  • 34.216.163.241
  • 54.212.243.205

Redshift by default prevents any external IP address from accessing your data warehouse so if you will need to add these IP addresses to your security groups. For more information, visit AWS Redshift Help Center. For Postgres data warehouses, you'll need to add these IPs in your firewall, and/or add rules to your pg_hba.conf file to only allow the Census user to connect to your database when using these IP addresses.