E-MapReduce:Manage metadata

Prerequisites

An EMR Serverless StarRocks instance is created. For more information, see Create an instance.

Limitations

• Common users cannot view the database size, the size of cached data, and the number of tables.

• Common users cannot view all tasks.

View metadata

1. Go to the StarRocks Manager page.

   1. Log on to the E-MapReduce console.

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

   3. In the top menu bar, select the desired region.

   4. Click StarRocks Manager, or click Connect in the Actions column for the target instance.

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

2. In the left-side navigation pane, 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 current catalog.

   Important

   By default, the audit log feature is enabled, and a database named _starrocks_audit_db_ and a table named starrocks_audit_tbl are automatically created. All subsequent audit logs are stored in this table. Do not delete the _starrocks_audit_db_ database and the starrocks_audit_tbl table. If you perform the deletion operation, the SQL task query feature cannot properly work in StarRocks Manager.

4. Click the name of the desired database to view detailed information about tables, views, and tasks in the database.

   Tab	Description
   Table	Displays all tables in the current database. You can click the name of a table to view related table information, partition information, node shards, and sharding information in sequence. The table information includes the table size and the size and type of cached data. Sorting by table size is supported. You can view information in ascending or descending order of the table size.
   Views	Displays detailed information about all views in the current database. Views are virtual tables defined based on SQL queries and do not store actual data. The main functional modules and their descriptions are as follows: View Details: displays all fields of the view and their properties, including field names, nullability, field types, and descriptions. Basic Information: displays table information, including basic information such as data catalog, database name, type, creation time, and last modification time. DDL: displays the SQL definition of the view (CREATE statement), helping you understand the query logic of the view and its dependencies on underlying tables. Preview Data: provides a data preview feature for the view, displaying the first 100 records. The data preview is dynamically calculated based on the view definition and reflects the real-time data state of the underlying physical tables.
   Materialized Views	Displays detailed information about all materialized views in the current database. Materialized views are physical tables defined based on SQL queries that store pre-computed results to accelerate complex queries. The main functional modules and their descriptions are as follows: Basic Information: displays core attributes of the materialized view, including ID, name, database, and other core attributes, along with the SQL definition of the view, helping you understand its query logic and dependencies on underlying tables. Task List: displays task records related to the materialized view, including task name, view name, database name, and other information. Dashboard: provides monitoring of the operational status and performance of the materialized view, including metrics such as storage volume, number of partitions, and table row count. Data Preview: provides a data preview feature for the materialized view, displaying the first 100 records.
   Tasks	Displays all tasks in the current database. Kafka Import Tasks: displays information about Routine Load tasks that import data from Kafka. Other Import Tasks: displays information about data import tasks other than Kafka import tasks. Note Stream Load tasks are synchronous import tasks and are not displayed in the task list. Export: displays information about tasks that export data to external storage using Export. Table Schema Change Tasks: displays information about tasks that modify table schemas using Schema Change. Materialized View Creation Tasks: displays information about all tasks related to materialized view creation in the current database.

Create a database

1. Go to the Create Database dialog box.

   You can access the Create Database dialog box using either of the following methods:

   • Method 1: From the Metadata Management page

     1. On the Metadata Management page, click the name of the catalog that you want to view.

     2. Click Create.

   • Method 2: From the StarRocks Manager page

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

2. In the Create Database dialog box, adjust the parameters as needed, and then click OK.

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

Create a table

1. Go to the Create Table dialog box.

   You can access the Create Table dialog box using either of the following methods:

   • Method 1: From the Metadata Management page

     1. On the Metadata Management page, click the name of the catalog that you want to view.

     2. Click the target database.

     3. On the Tables tab, click Create.

   • Method 2: From the StarRocks Manager page

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

2. In the Create Table dialog box, set basic information, columns, and properties, and then click OK.

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