PostgreSQL metadata store

To use this Apache Druid extension, include postgresql-metadata-storage in the extensions load list.

With the PostgreSQL extension, you can use PostgreSQL as a metadata store or ingest from a PostgreSQL database.

Set up PostgreSQL

To avoid issues with upgrades that require schema changes to a large metadata table, consider a PostgreSQL version that supports instant ADD COLUMN semantics.

1. Install PostgreSQL

   Use your favorite package manager to install PostgreSQL, e.g.:

• on Ubuntu/Debian using apt apt-get install postgresql
• on OS X, using Homebrew brew install postgresql

2. Create a druid database and user

   On the machine where PostgreSQL is installed, using an account with proper postgresql permissions:

   Create a druid user, enter diurd when prompted for the password.

   createuser druid -P

   Create a druid database owned by the user we just created

   createdb druid -O druid

   Note: On Ubuntu / Debian you may have to prefix the createuser and createdb commands with sudo -u postgres in order to gain proper permissions.

3. Configure your Druid metadata storage extension:

   Add the following parameters to your Druid configuration, replacing <host> with the location (host name and port) of the database.

   druid.extensions.loadList=["postgresql-metadata-storage"]
   druid.metadata.storage.type=postgresql
   druid.metadata.storage.connector.connectURI=jdbc:postgresql://<host>/druid
   druid.metadata.storage.connector.user=druid
   druid.metadata.storage.connector.password=diurd

Configuration properties

In most cases, the configuration options map directly to the postgres JDBC connection options.

Property	Description	Default	Required
druid.metadata.postgres.ssl.useSSL	Enables SSL	false	no
druid.metadata.postgres.ssl.sslPassword	The Password Provider or String password for the client's key.	none	no
druid.metadata.postgres.ssl.sslFactory	The class name to use as the SSLSocketFactory	none	no
druid.metadata.postgres.ssl.sslFactoryArg	An optional argument passed to the sslFactory's constructor	none	no
druid.metadata.postgres.ssl.sslMode	The sslMode. Possible values are "disable", "require", "verify-ca", "verify-full", "allow" and "prefer"	none	no
druid.metadata.postgres.ssl.sslCert	The full path to the certificate file.	none	no
druid.metadata.postgres.ssl.sslKey	The full path to the key file.	none	no
druid.metadata.postgres.ssl.sslRootCert	The full path to the root certificate.	none	no
druid.metadata.postgres.ssl.sslHostNameVerifier	The classname of the hostname verifier.	none	no
druid.metadata.postgres.ssl.sslPasswordCallback	The classname of the SSL password provider.	none	no
druid.metadata.postgres.dbTableSchema	druid meta table schema	public	no

PostgreSQL input source

The PostgreSQL extension provides an implementation of an SQL input source to ingest data into Druid from a PostgreSQL database. For more information on the input source parameters, see SQL input source.

{
  "type": "index_parallel",
  "spec": {
    "dataSchema": {
      "dataSource": "some_datasource",
      "dimensionsSpec": {
        "dimensionExclusions": [],
        "dimensions": [
          "dim1",
          "dim2",
          "dim3"
        ]
      },
      "timestampSpec": {
        "format": "auto",
        "column": "ts"
      },
      "metricsSpec": [],
      "granularitySpec": {
        "type": "uniform",
        "segmentGranularity": "DAY",
        "queryGranularity": {
          "type": "none"
        },
        "rollup": false,
        "intervals": null
      },
      "transformSpec": {
        "filter": null,
        "transforms": []
      }
    },
    "ioConfig": {
      "type": "index_parallel",
      "inputSource": {
        "type": "sql",
        "database": {
          "type": "postgresql",
          "connectorConfig": {
            "connectURI": "jdbc:postgresql://some-rds-host.us-west-1.rds.amazonaws.com:5432/druid",
            "user": "admin",
            "password": "secret"
          }
        },
        "sqls": [
          "SELECT * FROM some_table"
        ]
      },
      "inputFormat": {
        "type": "json"
      }
    },
    "tuningConfig": {
      "type": "index_parallel"
    }
  }
}