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    Data Lake Formation:Database tables and functions

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    Data Lake Formation:Database tables and functions

    Last Updated:Mar 26, 2026

    Data Lake Formation (DLF) organizes metadata in a three-level hierarchy:

    • Catalog — the top level; a single DLF instance can have multiple catalogs

    • Database — the second level; each catalog contains databases that group related tables

    • Table — the third level; each database contains tables that define the schema of your data

    This page explains how to create, view, edit, and delete databases, tables, and user-defined functions (UDFs) in the DLF console.

    Prerequisites

    Before you begin, ensure that you have:

    • Access to the DLF console

    • At least one catalog configured in DLF

    • The permissions required to create or modify metadata objects in that catalog

    Database

    Create a database

    1. Log on to the DLF console.

    2. In the left-side navigation pane, choose Metadata > Metadata.

    3. Click the Database tab, select a catalog from the Catalog List dropdown, and click Create Database.

    4. Configure the database parameters and click OK.

      Parameter Description
      Catalog The data catalog that will contain this database.
      Database Name The name of the database.
      Database Description (Optional) A description of the database.
      Select Path The Object Storage Service (OSS) path where database metadata is stored. Only Standard storage class OSS buckets are supported. If no Standard bucket exists in your region, create one in the OSS console.
    DLF creates a default database in each catalog automatically. The default database cannot be deleted. For production workloads, create a dedicated database instead.

    View database details

    1. Click the Database tab.

    2. In the database list, click the database name to view its Basic Information.

    3. Use the tabs to explore additional details:

      • Table List — tables in this database

      • Functions — user-defined functions registered to this database

      • Data Permission — access control settings

      • Data Overview — a summary of data stored in this database

      • Storage Rule — lifecycle and storage rules applied to this database

    Edit a database

    1. Click the Database tab, and select a catalog from Catalog List.

    2. Find the database and click Edit in the Actions column.

    3. Update the Database Description or Select Path, then click Update.

    Delete a database

    Important

    Deleting a database from DLF removes its metadata from the catalog but does not delete the data in OSS. To permanently delete the underlying data, run a DROP DATABASE statement from E-MapReduce or MaxCompute.

    1. Click the Database tab, and select a catalog from Catalog List.

    2. Find the database and click Delete in the Actions column.

    3. In the confirmation dialog box, click Delete.

    Table

    Create a table

    1. In the left-side navigation pane, choose Metadata > Metadata.

    2. Click the Table tab, select a catalog from Catalog List and a database from Database Name, then click Create Table.

    3. Configure the table parameters and click OK.

      Parameter Description
      Table Name The name of the table.
      Catalog The data catalog that contains this table.
      Database The database under the selected catalog.
      Table Description (Optional) A description of the table.
      Data Storage Location The OSS path where the table's data is stored. The default path follows the pattern oss://[database-storage-location]/[table-name].
      Format and Serialization The data format of the table. Supported formats: Avro, CSV, JSON, Parquet, and ORC.
      Delimiter (Optional) The column separator. Applies only when the data format is CSV.
      Common Column The non-partition columns of the table. For each column, specify a name, data type, and optional description.
      Partition Key Column The partition key columns of the table. For each column, specify a name, data type, and optional description.

    View table details

    1. Click the Table tab.

    2. In the table list, click the table name to view its Basic Information.

    3. Use the tabs to explore additional details:

      • Data Permission — access control settings

      • Data Overview — a summary of the data in this table. For details, see Data overview of data tables.

      • Version Management — the version history of the table schema

      • Storage Rule — lifecycle and storage rules applied to this table

    Edit a table

    1. Click the Table tab, and select a catalog from Catalog List and a database from Database Name.

    2. Find the table and click Edit in the Actions column.

    3. Modify the table information and click Update.

    Delete a table

    Important

    Deleting a table from DLF removes its metadata from the catalog but does not delete the data in OSS. To permanently delete the underlying data, run a DROP TABLE statement from E-MapReduce or MaxCompute.

    1. Click the Table tab, and select a catalog from Catalog List and a database from Database Name.

    2. Find the table and click Delete in the Actions column.

    3. In the confirmation dialog box, click Delete.

    Function

    Create a function

    1. In the left-side navigation pane, choose Metadata > Metadata.

    2. Click the Function tab, select a catalog from Catalog List and a database from Database Name, then click Create Function.

    3. Configure the function parameters and click OK.

      Parameter Description
      Function Name The name of the function.
      Function Type Set to JAVA. Only JAVA functions are supported.
      Catalog The data catalog that contains this function.
      Database The database under the selected catalog.
      Class Name (Optional) Enter the class name.
      Resource URI (Optional) The JAR, FILE, or ARCHIVE resources the function depends on. Click Add Column and enter the resource Type and URI.

    View function details

    1. Click the Function tab, and select a catalog from Catalog List and a database from Database Name.

    2. In the function list, click the function name to view its basic information.

    Edit a function

    1. Click the Function tab, and select a catalog from Catalog List and a database from Database Name.

    2. Find the function and click Edit in the Actions column.

    3. Update the Class Name and click OK.

    Delete a function

    1. Click the Function tab, and select a catalog from Catalog List and a database from Database Name.

    2. Find the function and click Delete in the Actions column.

    3. In the confirmation dialog box, click Delete.