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    E-MapReduce:Manage metadata

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    E-MapReduce:Manage metadata

    Last Updated:Sep 21, 2026

    The metadata management feature displays information about the databases, tables, partitions, and tasks of the current instance. You can also create databases and tables, and define their columns and properties.

    Prerequisites

    The StarRocks instance is created. For more information, see Create an instance.

    Limits

    • Regular users cannot view the database size, cached data size, or table count information.

    • Regular users cannot view the complete task list.

    View metadata

    1. Go to the StarRocks Manager page.

      1. Log on to the E-MapReduce console.

      2. In the left navigation pane, choose EMR Serverless > StarRocks.

      3. In the top menu bar, select a region as needed.

      4. Click StarRocks Manager, or click Connect in the Actions column of the created instance.

        For more information on connecting to a StarRocks instance, see Connect to a StarRocks instance by using EMR StarRocks Manager.

    2. In the navigation pane on the left, click Metadata Management.

    3. On the Catalogs page, click the name of the catalog that you want to view.

      This page displays all databases in the selected catalog.

      Important

      The audit log feature is enabled by default and automatically creates the _starrocks_audit_db_ database and the starrocks_audit_tbl table. All subsequent audit logs are stored in this table. Do not delete the _starrocks_audit_db_ database or the starrocks_audit_tbl table, as doing so will cause the SQL task query feature in Manager to fail.

    4. Click the name of the database that you want to view to see details about its tables, views, and tasks.

      Tab

      Description

      Table

      Displays all tables in the current database. Click a table name to view its details, including table size, cached data size, type, partition information, node sharding status, and shard information. You can sort the tables by size in ascending or descending order.

      Views

      Displays details of all views in the current database. A view is a virtual table defined by an SQL query and does not store actual data.

      • View Details: Displays all fields and their properties, including field name, nullability, field type, and description.

      • Basic Information: Displays table information, including data catalog, database name, type, creation time, and last modification time.

      • DDL: Displays the SQL definition (CREATE statement) of the view. This helps you understand the query logic and the underlying tables it depends on.

      • Data Preview: Provides a preview of the view's data, showing the first 100 records. The data preview is dynamically calculated based on the view's definition and reflects the real-time state of the underlying physical tables.

      Materialized View

      Displays details of all materialized views in the current database. A materialized view is a physical table defined by an SQL query. It stores pre-calculated results to speed up complex queries.

      • Basic Information: Displays the core properties of the materialized view, such as ID, name, and database. Also shows the view's SQL definition for understanding its query logic and dependent underlying tables.

      • Tasks: Displays task records related to the materialized view, including task name, view name, and database name.

      • Monitoring Dashboard: Provides performance monitoring and status for the materialized view, including metrics such as storage size, partition count, and row count.

      • Data Preview: Provides a preview of the materialized view's data, showing the first 100 records.

      Tasks

      Displays all tasks in the current database.

      • Kafka Import: Displays tasks for importing data from Kafka using Routine Load.

      • Other Imports: Displays data import tasks other than Kafka imports.

        Note

        Stream Load is a synchronous import task and is not displayed in this task list.

      • Export: Displays tasks for exporting data to external storage using the Export method.

      • Table Schema Change: Displays tasks for modifying the table schema using Schema Change.

      • Materialized View Creation: Displays all tasks related to the creation of materialized views in the current database.

    Create a DLF catalog

    1. Open the Create Catalog dialog box.

      You can open the Create Catalog dialog box in two ways:

      • Method 1: On the Metadata Management page

        On the Metadata Management page, click Create Catalog.

      • Method 2: On the StarRocks Manager page

        In the navigation pane on the left of the EMR StarRocks Manager page, choose Create > Catalog.

    2. In the Add Data Catalog dialog box, configure the parameters.

      Parameter

      Description

      Catalogs

      Select DLF Data Catalog.

      Catalog Name

      Enter a catalog name of 2 to 64 characters. Only letters, digits, hyphens (-), periods (.), and underscores (_) are allowed.

      DLF Catalog

      Select a created DLF data catalog from the drop-down list. To create a DLF data catalog, go to the DLF console.

      Data Type

      Select Paimon or Iceberg.

      • Paimon: For high-performance data lake scenarios.

      • Iceberg: For large-scale data analytics scenarios.

      User Information

      The system automatically displays the current user and the associated RAM user.

      If no RAM user is associated, you cannot access the DLF data catalog after the DLF catalog is created.

    3. Confirm the configuration and click OK to create the DLF catalog.

    Create a database

    1. Open the Create Database dialog box.

      You can open the Create Database dialog box in two ways:

      • Method 1: On the Metadata Management page

        1. On the Metadata Management page, click the name of the target catalog.

        2. Click Create.

      • Method 2: On the StarRocks Manager page

        In the navigation pane on the left of the EMR StarRocks Manager page, choose Create > Database.

    2. In the Create Database dialog box, configure the parameters as required and click OK.

      You can view the SQL statement for creating the database in the Preview area. For more information, see CREATE DATABASE.

    Create a table

    1. Open the Create Table dialog box.

      You can open the Create Table dialog box in two ways:

      • Method 1: On the Metadata Management page

        1. On the Metadata Management page, click the name of the target catalog.

        2. Click the target database.

        3. On the Table tab, click Create.

      • Method 2: On the StarRocks Manager page

        In the navigation pane on the left of the EMR StarRocks Manager page, choose Create > Table.

    2. In the Create Table dialog box, configure the metadata, such as basic information, columns, and properties, and then click OK.

      You can view the SQL statement for creating the table in the Preview area. For more information, see CREATE TABLE.

    FAQ

    • Q1: Why can't I access data after creating a DLF catalog?

      A: Confirm that the associated RAM user has read and write permissions on the DLF data catalog in the DLF console.

    • Q2: Why is the DLF data catalog drop-down list empty, or why is a newly added data catalog not displayed?

      A: No DLF data catalogs are available for the current account, or the existing catalogs have not been authorized for the current RAM user. Go to the DLF console to create a data catalog and add the required access policy for the RAM user.