Hologres:Connect to HoloWeb

Step 1: Open HoloWeb

1. Log on to the Hologres Management Console.

2. In the navigation pane on the left of the top menu bar, select the region where your instance resides.

3. Click Go to HoloWeb to open the HoloWeb development page.

Step 2: Connect a Hologres instance

1. On the Metadata Management tab, click Instances.

2. In the Instances dialog box, configure the connection parameters and click OK.

   Parameter	Description	Required
   Network type	Public Network: Available in China (Shanghai), China (Shenzhen), China (Beijing), China (Hangzhou), China (Zhangjiakou), Singapore, China (Hong Kong), Malaysia (Kuala Lumpur), Indonesia (Jakarta), and US (Silicon Valley). Virtual Private Cloud (VPC): Available only in the region where HoloWeb is logged on. VPC-type instances cannot be edited or deleted.	No
   Instance name	Select an instance created under your current account. If the instance does not appear immediately after purchase, enter the Domain name and Port manually.	No
   Name	Defaults to the selected instance name. Enter a custom name if needed.	Yes
   Description	A description for the connection.	No
   Domain name	The domain name of the Hologres instance. Find it in the Network Information section of the instance details page in the Hologres Management Console. Selecting an Instance name fills this field automatically.	Yes
   Port	The port of the Hologres instance. Find it in the Network Information section. Selecting an Instance name fills this field automatically.	Yes
   Logon method	Password-free logon: Log on directly using your current account — no credentials required. Password logon: Enter the username and password of the account to use.	Yes
   Username	Required only for Password logon. Enter the AccessKey ID of the account. Get it from AccessKey Management.	No
   Password	Required only for Password logon. Enter the AccessKey secret of the account.	No
   Test connectivity	Click to verify the connection. The test is successful. indicates success; The test failed. indicates failure.	No
   Log on after connecting	Yes: The instance appears in the logged-on instances list on the left. No: The instance appears in the not logged-on instances list.	Yes

Step 3: Create a database

After activating a Hologres instance, the system automatically creates a postgres database. This database has minimal resource allocation and is intended only for management tasks — do not use it for business workloads. Create a new database for your applications.

If you already have a database, skip to Step 4: Run a SQL query.

1. Click Metadata Management > Database. Alternatively, in the Metadata Management page, find the Logged On Instances list, right-click the target connection, and select Create Database.

   

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

   Parameter	Description
   Instance name	The logged-on instance where the database resides. Filled in automatically.
   Database name	A unique name for the database.
   Access policy	The permission model for the database. Choose from: SPM, SLPM, or the standard PostgreSQL authorization model.
   Log on immediately	Yes: Use the database immediately after creation. No: Log on to the database before using it.

   

Step 4: Run a SQL query

Use standard PostgreSQL syntax in the SQL Editor to query your Hologres instance.

1. On the SQL Editor page, click the icon to create a query. Alternatively, right-click My SQL Queries in the left navigation pane and select Create SQL Query. For more information, see SQL window.

2. On the Ad-hoc Query page, select the Instance name and Database. Paste the following sample statements into the editor and click Run.

   SQL queries are not case-sensitive for table names and field names. To run a case-sensitive query against a table name, enclose it in double quotation marks ("").

   BEGIN;
   CREATE TABLE nation (
    n_nationkey bigint NOT NULL,
    n_name text NOT NULL,
    n_regionkey bigint NOT NULL,
    n_comment text NOT NULL,
   PRIMARY KEY (n_nationkey)
   );
   CALL SET_TABLE_PROPERTY('nation', 'bitmap_columns', 'n_nationkey,n_name,n_regionkey');
   CALL SET_TABLE_PROPERTY('nation', 'dictionary_encoding_columns', 'n_name,n_comment');
   CALL SET_TABLE_PROPERTY('nation', 'time_to_live_in_seconds', '31536000');
   COMMIT;
   
   INSERT INTO nation VALUES
   (11,'zRAQ', 4,'nic deposits boost atop the quickly final requests? quickly regula'),
   (22,'RUSSIA', 3  ,'requests against the platelets use never according to the quickly regular pint'),
   (2,'BRAZIL',  1 ,'y alongside of the pending deposits. carefully special packages are about the ironic forges. slyly special '),
   (5,'ETHIOPIA',  0 ,'ven packages wake quickly. regu'),
   (9,'INDONESIA', 2  ,'slyly express asymptotes. regular deposits haggle slyly. carefully ironic hockey players sleep blithely. carefull'),
   (14,'KENYA',  0  ,'pending excuses haggle furiously deposits. pending, express pinto beans wake fluffily past t'),
   (3,'CANADA',  1 ,'eas hang ironic, silent packages. slyly regular packages are furiously over the tithes. fluffily bold'),
   (4,'EGYPT', 4 ,'y above the carefully unusual theodolites. final dugouts are quickly across the furiously regular d'),
   (7,'GERMANY', 3 ,'l platelets. regular accounts x-ray: unusual, regular acco'),
   (20 ,'SAUDI ARABIA',  4 ,'ts. silent requests haggle. closely express packages sleep across the blithely');
   
   SELECT * FROM nation;

3. View the query results in the Result [1] section below the editor.

   

Prerequisites

Before creating a foreign table, make sure that you have:

• Created a MaxCompute project with a source table and data loaded. You can use DataWorks to set this up, or use a local MaxCompute client to create the table and write data to it.

• Logged on to a database in HoloWeb (required for MaxCompute and OSS data lake acceleration).

Create a foreign table

1. Click Metadata Management > MaxCompute Query Acceleration > Create Foreign Table.

2. In the Create Foreign Table dialog box, select an acceleration mode and configure the parameters, then click Submit.

   Whole-database acceleration

   Category	Parameter	Description
   Acceleration method	Select an acceleration method	Select Entire Project.
   MaxCompute data source	Project name	The name of the MaxCompute project.
   	Schema name	The MaxCompute schema name. Required only for projects with schemas enabled. For more information, see Schema operations.
   Destination table position	Holo schema	The target Hologres schema. Select the default public schema or a custom schema.
   Advanced settings	Processing rule for table name conflicts	Choose how to handle conflicts: Ignore and continue to create other tables, Update and modify the table with the same name, or Report an error and do not create the table again.
   	Processing rule for unsupported data types	Choose: Report an error and fail the import or Ignore and skip table of unsupported fields.

   Partial acceleration

   Category	Parameter	Description
   Acceleration method	Select an acceleration method	Select Selected Tables.
   MaxCompute data source	Project name	The name of the MaxCompute project.
   	Schema name	The MaxCompute schema name. Required only for projects with schemas enabled. For more information, see Schema operations.
   	Search	Fuzzy search by table name. Up to 200 tables are displayed.
   Destination table position	Holo schema	The target Hologres schema. Select the default public schema or a custom schema.
   Advanced settings	Processing rule for table name conflicts	Choose: Ignore and continue to create other tables, Update and modify the table with the same name, or Report an error and do not create a duplicate.
   	Processing rule for unsupported data types	Choose: Report an error and fail the import or Ignore and skip table of unsupported fields.

   Single-table acceleration

   Category	Parameter	Description
   Acceleration method	Select an acceleration method	Select Single Table.
   MaxCompute data source	Project name	The name of the MaxCompute project.
   	Schema name	The MaxCompute schema name. Required only for projects with schemas enabled. For more information, see Schema operations.
   	Table name	The source table in the MaxCompute schema. Fuzzy search by table name prefix is supported.
   Destination Hologres table	Schema	The target Hologres schema. Select the default public schema or a custom schema.
   	Table name	The name for the foreign table in Hologres.
   	Destination table description	A description of the foreign table.

3. After the foreign table is created, go to Metadata Management > Logged On Instances in the left navigation pane, double-click the foreign table, and click Data Preview to query the MaxCompute data.

Log on to a database

1. Log on to the Hologres console. Click Instances, then click the instance in the Instance ID/Name column to go to the Instance Details page. In the upper-right corner, click Connect to Instance to open HoloWeb.

2. In the top menu bar, click Database > Log On to Database. In the dialog box, select the virtual warehouse, set Select Database to Existing Database, choose the database from the Database Name drop-down list, and click OK. HoloWeb refreshes automatically.

Create an internal table

1. In the top menu bar, click Metadata Management > Create Table. Alternatively, in the Metadata Management page, find the Logged On Instances list, click the target database, right-click the target schema, and select Create Internal Table.

2. On the Create Internal Table page, configure the parameters.

   Parameter descriptions (click to expand)

   Category	Parameter	Description
   Basic properties	Schema	The schema for the table. Select the default public schema or a custom schema.
   	Table name	A name for the internal table.
   	Description	A description of the table.
   Fields	Field name	The column identifier.
   	Data type	The data type for the column.
   	Primary key	The unique row identifier.
   	Nullable	Whether the column allows null values.
   	Array	Whether the column holds an ordered sequence of elements.
   	Description	A description of the column.
   	Operation	Delete, Up, or Down to manage column order.
   Properties	Storage mode	Column-oriented storage (default), Row-oriented storage, or Row-column storage.
   	Table data TTL (days)	Time to live (TTL) for table data, calculated from the first write. When the TTL expires, data is purged within a variable period. Default: Permanent.
   	Binary logging	Whether to enable binary logging. See Subscribe to Hologres binary logs.
   	Binary logging lifecycle	The lifecycle of binary logging. Default: Permanent. See Subscribe to Hologres binary logs.
   	Distribution column	distribution_key. See Distribution key.
   	Segment column	event_time_column. See Event Time Column (Segment Key).
   	Clustering column	clustering_key. See Clustering Key.
   	Dictionary encoding column	dictionary_encoding_columns. See Dictionary Encoding.
   	Bitmap column	bitmap_columns. See Bitmap Index.
   Partitioned table	—	Select a partition field.

3. Click Submit in the upper-right corner. Refresh the target schema in the left navigation pane to see the new table.

Manage internal tables

• Edit a table: In the Logged On Instances list, double-click the table, click Edit Table, make your changes (add fields, modify the data lifecycle, etc.), and click Submit.

• Delete a table: Right-click the table in the Logged On Instances list, select Delete Table, and click OK.

• Preview table data: Double-click the table, then click Data Preview on the table information tab.

• Preview a DDL statement: On the table information tab, click DDL Statements.