Create a Hologres SQL node - DataWorks - Alibaba Cloud Documentation Center

A Hologres SQL node lets you run standard PostgreSQL queries on large-scale data in MaxCompute directly from DataWorks, without migrating your data.

Prerequisites

Before you begin, make sure you have a Hologres compute engine instance added on the Workspace Configurations page. For details, see Configure a workspace.

Develop and run a Hologres SQL node

Step 1: Write your SQL

Write your SQL in the editor.

To pass values dynamically at runtime, define variables using the ${variable_name} syntax, then assign values to those variables in the Schedule panel on the right. For more information, see Parameters.

SELECT col_1, col_2 FROM your_table_name WHERE pt > ${pt_num} LIMIT 500;

Note

Queries return a maximum of 200 rows by default. To display more rows, add a LIMIT clause to your SELECT statement. The maximum you can display is 10,000 rows.

Step 2: Configure and run the task

In the Run Configuration panel, select the computing resource and resource group for this task.
Note
To access data sources over the public network or in a VPC environment, use a scheduling resource group that can connect to the data source. For details, see Network connectivity solutions.
From the Select Data Source drop-down list in the toolbar, select your Hologres data source. Click Run.
Click Save.

Step 3: Configure scheduling

To run this node on a schedule, configure its scheduling settings. For details, see Node scheduling configuration.

Step 4: Deploy the node

After configuring the node, deploy it to make it active. For details, see Node and workflow deployment.

Step 5: Monitor in Operation Center

After deployment, track the status of your periodic task in Operation Center. For details, see Getting started with Operation Center.