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Iceberg REST Catalog

Dremio connects to any catalog supporting the Iceberg REST Catalog specification. See Supported Configurations below for ready-to-use configurations for many popular catalogs, including:

In addition, Dremio provides specific connectors for:

Connect to an Iceberg REST Catalog​

  1. In the Dremio console, click Add Data on the Home page.
  2. In the Add Data dialog, select Iceberg REST Catalog.
  3. Configure the connection using the sections below, then click Save.

General​

  1. For Name, enter a name for the connection. The name you enter must be unique in the organization. Also, consider a name that is easy for users to reference. This name cannot be edited once the connection is created. The name cannot exceed 255 characters and must contain only the following characters: 0-9, A-Z, a-z, underscore (_), or hyphen (-).
  2. For Endpoint URI, specify the catalog service URI.
  3. By default, Use vended credentials is turned on. This allows Dremio to connect to the catalog and receive temporary credentials for the underlying storage location. When this setting is enabled, you do not need to add storage authentication in Advanced Options. If you experience errors using vended credentials, turn the setting off and provide credentials via Advanced Options to establish a connection.
  4. (Optional) For Allowed Namespaces, add each namespace and check the option if you want to include their entire subtrees. Tables are organized into namespaces, which can be at the top level or nested within one another. Namespace names cannot contain periods or spaces.

Advanced Options​

Storage Authentication

If you disabled vended credentials in the General tab, you must manually provide storage authentication.

Dremio supports Amazon S3 and Azure Storage as object storage services. For acceptable storage authentication configurations, see the following catalog properties and credentials for each service option.

  • fs.s3a.aws.credentials.provider (property)

    • Value: org.apache.hadoop.fs.s3a.SimpleAWSCredentialsProvider
    • Description: Required field for an Iceberg REST Catalog.

  • fs.s3a.access.key (credential)

    • Value: <your_access_key>
    • Description: AWS access key ID used by the S3A file system. Omit for IAM role-based or provider-based authentication.

  • fs.s3a.secret.key (credential)

    • Value: <your_secret_key>
    • Description: AWS secret access key used by the S3A file system. Omit for IAM role-based or provider-based authentication.

Cache Options

  • Enable local caching when possible: Selected by default. Along with asynchronous access for cloud caching, local caching can improve query performance.
  • Max percent of total available cache space to use when possible: Specifies the disk quota, as a percentage, available on any single executor node when local caching is enabled. The default is 100 percent of the total disk space available on the mount point provided for caching. You can either manually enter a percentage in the value field or use the arrows to the far right to adjust the percentage.

Reflection Refresh​

You can set the policy that controls how often Reflections are scheduled to be refreshed automatically, as well as the time limit after which Reflections expire and are removed.

Refresh Settings

  • Never refresh: Prevent automatic Reflection refresh. By default, Reflections refresh automatically.
  • Refresh every: Set the refresh interval in hours, days, or weeks. Ignored if Never refresh is selected.
  • Set refresh schedule: Specify a daily or weekly refresh schedule.

Expire Settings

  • Never expire: Prevent Reflections from expiring. By default, Reflections expire after the configured time limit.
  • Expire after: The time limit after which Reflections are removed from Dremio, specified in hours, days, or weeks. Ignored if Never expire is selected.

Metadata​

Dataset Handling

  • Remove dataset definitions if underlying data is unavailable (default).

Dataset Discovery

  • Fetch every: You can choose to set the frequency to fetch object names in minutes, hours, days, or weeks. The default frequency to fetch object names is 1 hour.

Dataset Details

  • Fetch mode: You can choose to fetch only from queried datasets. Dremio updates details for previously queried objects. By default, this is set to Only Queried Datasets.
  • Fetch every: You can choose to set the frequency to fetch dataset details in minutes, hours, days, or weeks. The default frequency to fetch dataset details is 1 hour.
  • Expire after: You can choose to set the expiry time of dataset details in minutes, hours, days, or weeks. The default expiry time of dataset details is 3 hours.

Privileges​

This connection inherits privileges from Project settings. To grant specific users or roles additional privileges in this connection:

  1. Enter the username or role name that you want to grant access to and click the Add to Privileges button. The added user or role is displayed in the USERS/ROLES table.
  2. For the users or roles in the USERS/ROLES table, toggle the checkmark for each privilege you want to grant on the Dremio source that is being created.
  3. Click Save after setting the configuration.

See Privileges for additional information about privileges.

Edit an Iceberg REST Catalog Connection​

  1. On the Open Catalog page, under Connections, right-click the connection and select Settings.
  2. Update the connection configuration as needed.
  3. Click Save.

Delete an Iceberg REST Catalog Connection​

note

If the source is in a bad state (for example, Dremio cannot authenticate to the source or the source is otherwise unavailable), only users who belong to the ADMIN role can delete the source.

  1. On the Open Catalog page, under Connections, right-click the connection and select Delete.
  2. Click Delete to confirm.

Supported Configurations​

Select your catalog type below.

General Settings

  • Endpoint URI: http://localhost:8181/api/catalog
  • Use vended credentials: Unchecked

Advanced Options – Catalog Properties

  • warehouse: polaris_oss_catalog
  • scope: PRINCIPAL_ROLE:ALL
  • fs.s3a.aws.credentials.provider: org.apache.hadoop.fs.s3a.SimpleAWSCredentialsProvider

Advanced Options – Catalog Credentials

  • fs.s3a.access.key: <s3AccessKey>
  • fs.s3a.secret.key: <s3SecretKey>
  • credential: <client_id:client_secret>