Postgres

Prerequisites

The hostname for the Postgres (opens in a new tab) database server
The username/password for the Postgres (opens in a new tab) database server
The name of the database to use within the Postgres (opens in a new tab) database server

Setup

Manual

Add the following to a .env file in your Cube project:

CUBEJS_DB_TYPE=postgres
CUBEJS_DB_HOST=my.postgres.host
CUBEJS_DB_NAME=my_postgres_database
CUBEJS_DB_USER=postgres_user
CUBEJS_DB_PASS=**********

Environment Variables

Environment Variable	Description	Possible Values	Required
`CUBEJS_DB_HOST`	The host URL for a database	A valid database host URL	✅
`CUBEJS_DB_PORT`	The port for the database connection	A valid port number	❌
`CUBEJS_DB_NAME`	The name of the database to connect to	A valid database name	✅
`CUBEJS_DB_USER`	The username used to connect to the database	A valid database username	✅
`CUBEJS_DB_PASS`	The password used to connect to the database	A valid database password	✅
`CUBEJS_DB_SSL`	If `true`, enables SSL encryption for database connections from Cube	`true`, `false`	❌
`CUBEJS_CONCURRENCY`	The number of concurrent connections each queue has to the database. Default is `2`	A valid number	❌
`CUBEJS_DB_MAX_POOL`	The maximum number of concurrent database connections to pool. Default is `8`	A valid number	❌

Pre-Aggregation Feature Support

count_distinct_approx

Measures of type count_distinct_approx can only be used in pre-aggregations when using the Postgres HLL extension (opens in a new tab) with Postgres as a source database.

Pre-Aggregation Build Strategies

To learn more about pre-aggregation build strategies, head here.

Feature	Works with read-only mode?	Is default?
Batching	✅	✅
Export Bucket	-	-

By default, Postgres uses batching to build pre-aggregations.

Batching

No extra configuration is required to configure batching for Postgres.

Export Bucket

Postgres does not support export buckets.

SSL

To enable SSL-encrypted connections between Cube and Postgres, set the CUBEJS_DB_SSL environment variable to true. For more information on how to configure custom certificates, please check out Enable SSL Connections to the Database.

Additional Configuration

AWS RDS

Use CUBEJS_DB_SSL=true to enable SSL if you have SSL enabled for your RDS cluster. Download the new certificate here (opens in a new tab), and provide the contents of the downloaded file to CUBEJS_DB_SSL_CA. All other SSL-related environment variables can be left unset. See the SSL section for more details. More info on AWS RDS SSL can be found here (opens in a new tab).

Google Cloud SQL

You can connect to an SSL-enabled MySQL database by setting CUBEJS_DB_SSL to true. You may also need to set CUBEJS_DB_SSL_SERVERNAME, depending on how you are connecting to Cloud SQL (opens in a new tab).

Heroku

Unless you're using a Private or Shield Heroku Postgres database, Heroku Postgres does not currently support verifiable certificates. Here is the description of the issue from Heroku (opens in a new tab).

As a workaround, you can set rejectUnauthorized option to false in the Cube Postgres driver:

const PostgresDriver = require("@cubejs-backend/postgres-driver");
module.exports = {
  driverFactory: () =>
    new PostgresDriver({
      ssl: {
        rejectUnauthorized: false,
      },
    }),
};

Oracle Presto